CN115377659A

CN115377659A - Antenna and foldable electronic equipment

Info

Publication number: CN115377659A
Application number: CN202110535798.XA
Authority: CN
Inventors: 冯堃; 吴鹏飞; 应李俊; 侯猛; 王汉阳
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-05-17
Filing date: 2021-05-17
Publication date: 2022-11-22
Also published as: WO2022242357A1

Abstract

The embodiment of the application provides an antenna and a foldable electronic device, wherein the foldable electronic device comprises a rotating shaft, a first body and a second body, the antenna comprises a first radiating body and a second radiating body, the first radiating body is arranged in the first body, the second radiating body is arranged in the second body, the first radiating body and the second radiating body are grounded at the rotating shaft, the first radiating body inputs an electric signal through a first feed point, the second radiating body inputs an electric signal through a second feed point, the first feed point is connected with the second feed point through a radio frequency connecting line, a first gap is formed in the first radiating body, and a second gap is formed in the second radiating body; by setting the positions of the first feeding point and the second feeding point and controlling the phase difference of the electric signals reaching the first feeding point and the second feeding point, an antenna with high efficiency and low SAR value can be constructed. The embodiment of the application provides an antenna and a foldable electronic device, and high efficiency and low SAR value of the antenna can be achieved.

Description

Antenna and foldable electronic equipment

Technical Field

The application relates to the technical field of electronic equipment, in particular to an antenna and foldable electronic equipment.

Background

With the continuous development of wireless communication technology, more and more electronic devices, such as mobile phones, earphones, tablet computers, wearable devices or data cards, appear in people's daily life. When the electronic device performs normal communication, electromagnetic radiation is generated, and the electromagnetic radiation with too high intensity may affect human health. Therefore, each country and region generally has relatively strict regulations on head specific absorption rate (head SAR) and body SAR of electronic devices. For the antenna design of the foldable electronic device, the antenna design difficulty is high because the efficiency and SAR value of the antenna in the unfolded state and the folded state need to be considered.

Disclosure of Invention

The embodiment of the application provides an antenna and a foldable electronic device, and high efficiency and low SAR value of the antenna can be achieved.

An aspect of an embodiment of the present application provides an antenna, which is applied to a foldable electronic device, where the foldable electronic device includes a rotating shaft, and a first body and a second body disposed on two sides of the rotating shaft, and the antenna includes a feed source, a first radiator, a second radiator, a first feed point, a second feed point, and a radio frequency connection line;

the first radiator is arranged in the first main body, the second radiator is arranged in the second main body, one end of the first radiator close to the rotating shaft is grounded, one end of the second radiator close to the rotating shaft is grounded, the first radiator feeds an electric signal through a first feeding point, the second radiator feeds an electric signal through a second feeding point, the first feeding point is connected with the second feeding point through a radio frequency connecting line, a first gap is formed in the first radiator, and a second gap is formed in the second radiator;

the positions of the first feeding point and the second feeding point and the phases of the electric signals of the first feeding point and the second feeding point are set as follows:

the first feeding point and the second feeding point are arranged between the first gap and the second gap, and the phases of the electric signals of the first feeding point and the second feeding point are opposite; alternatively, the first and second electrodes may be,

the first feeding point is arranged on one side of the first gap far away from the second gap, the second feeding point is arranged on one side of the second gap far away from the first gap, and the phases of the electric signals of the first feeding point and the second feeding point are opposite; alternatively, the first and second liquid crystal display panels may be,

the first feeding point is arranged between the first gap and the second gap, the second feeding point is arranged on one side of the second gap far away from the first gap, or the first feeding point is arranged on one side of the first gap far away from the second gap, the second feeding point is arranged between the first gap and the second gap, and the phases of electric signals of the first feeding point and the second feeding point are in the same phase.

The embodiment of the application provides an antenna, space on utilizing two main parts of collapsible electronic equipment sets up the radiator respectively, two irradiators pass through the radio frequency connecting wire and connect and constitute distributed antenna, through the phase difference of control feed-in both sides irradiator signal, realize showing the current of symmetric distribution on the at least part irradiator of pivot both sides under the expansion state, two irradiators constitute adjacent parallel irradiators under the fold state, and the current syntropy on the at least part parallel irradiator distributes, thereby can realize the high efficiency and the low SAR value of antenna.

In a possible embodiment, the antenna further comprises a phase shifter connected between the first feeding point and the second feeding point.

The phase difference between the electrical signal arriving at the first and second feed points can also be controlled by adding means capable of adjusting the phase of the wave, such as a phase shifter, to the radio frequency connection.

In one possible embodiment, the phase shifter is arranged in the first body or in the second body.

The phase shifter may be disposed in the first body or the second body to improve flexibility of positional arrangement.

In one possible embodiment, the first radiator and the second radiator are disposed axisymmetrically with respect to the rotation axis, and the first slit and the second slit are disposed axisymmetrically with respect to the rotation axis. The requirement of antenna efficiency is met, and meanwhile, the overall appearance of the foldable electronic equipment is not influenced.

When the first radiator and the second radiator are arranged in axial symmetry relative to the rotating shaft, the common mode of the line antenna taking the rotating shaft as the center is favorably constructed when the electronic equipment is in an unfolded state, and currents which are adjacent and in the thickness direction of the electronic equipment are distributed in the same direction when the electronic equipment is in a folded state, so that the efficiency of the antenna is improved, and the SAR value of the antenna is reduced.

In a possible embodiment, a third slot is further disposed on the first radiator, a fourth slot is further disposed on the second radiator, the third slot is located on a side of the first slot facing away from the second radiator, and the fourth slot is located on a side of the second slot facing away from the first radiator; the first feeding point and the second feeding point are both arranged between the third slot and the fourth slot.

The first radiator and the second radiator, which are located between the third slot and the fourth slot, constitute the radiator of the antenna provided in the embodiment of the present application, so as to limit the length of the radiator of the antenna.

In one possible embodiment, the radio frequency connection line comprises a cable or a flexible circuit board.

The radio frequency connecting wires such as cables, flexible circuit boards and the like can control the phase difference of the electric signals reaching the first feeding point and the second feeding point by controlling the length.

In a possible implementation manner, when the foldable electronic device is in the unfolded state, the extending direction of the first radiator and the second radiator is perpendicular to the extending direction of the rotating shaft, and the distance between the first radiator and the second radiator is smaller than the width of the rotating shaft; when the foldable electronic device is in a folded state, the extending directions of the first radiator and the second radiator are consistent, and the first radiator and the second radiator are overlapped in the thickness direction of the foldable electronic device.

When the electronic equipment is in an unfolded state, the first radiating body and the second radiating body are in axial symmetry distribution relative to the rotating shaft, and the distance between the first radiating body and the second radiating body is smaller than the width of the rotating shaft, so that the common mode of the line antenna taking the rotating shaft as the center is favorably constructed, and the space of the electronic equipment can be reasonably utilized to arrange the antenna.

In one possible embodiment, when the foldable electronic device is in the unfolded state, the currents on the first radiator and the second radiator are distributed in opposite directions; when the foldable electronic device is in a folded state, the currents on the first radiator and the second radiator are distributed in the same direction.

In the unfolded state, the current distribution can form a common mode of the linear antenna so as to improve the efficiency of the antenna and reduce the SAR value, and in the folded state, the current distribution in the same direction has small interference, so that the high efficiency and the low SAR value of the antenna can be ensured.

In one possible embodiment, the first radiator is electrically connected to the rotating shaft to be grounded through the rotating shaft, and the second radiator is electrically connected to the rotating shaft to be grounded through the rotating shaft.

The first radiator and the second radiator are grounded through the rotating shaft, so that the grounding structure of the antenna can be simplified, and the compactness of the spatial arrangement of the antenna is improved.

In a possible embodiment, a gap is provided between the first radiator and the floor, the electrical connection between the first radiator and the floor constitutes a slot, the electrical connection between the second radiator and the floor constitutes a slot, and the electrical connection between the second radiator and the floor constitutes a slot.

Feeding an electric signal to a first radiator, wherein the first radiator and the ground can be regarded as forming a slot antenna; feeding the second radiator with an electrical signal, the second radiator and ground may be considered to form a slot antenna.

In a possible embodiment, tuning switches are disposed on the first radiator, two tuning switches are disposed on two sides of the first slot, respectively, and tuning switches are disposed on the second radiator, two tuning switches are disposed on two sides of the second slot, respectively.

The tuning switch may be arranged to adjust the resonant frequency of the first and second resonances of the first and second radiators, respectively.

Another aspect of the embodiments of the present application provides a foldable electronic device, which includes a rotating shaft, a first body and a second body disposed on two sides of the rotating shaft, and an antenna provided in the above embodiments.

The foldable electronic device provided by the embodiment of the application forms a distributed antenna by respectively arranging the radiators on two sides of the rotating shaft, the radiators on the two sides are connected through the radio frequency connecting line, and the phase difference of an electric signal reaching the radiators on the two sides is controlled, so that when the foldable electronic device is in an unfolded state, a common mode of the linear antenna can be formed, and when the electronic device is in a folded state, because the current directions of at least part of adjacent parallel radiation branches on the first main body and the second main body are basically consistent, the foldable electronic device can achieve high efficiency and low SAR value in the unfolded state and the folded state.

In one possible implementation, the electronic device includes a metal frame, and the metal frames located on two sides of the rotation axis respectively form a first radiator and a second radiator.

The metal frames on two sides of the rotating shaft are used as radiating bodies of the antenna, so that the antenna is simple in structure and easy to realize.

In one possible implementation, a portion of the length of the top frame at the top of the electronic device or the bottom frame at the bottom of the electronic device forms the first radiator and the second radiator.

The top frame or the bottom frame of the electronic equipment is used as a radiator of the antenna, which is beneficial to realizing an axisymmetric structure, so that the foldable electronic equipment can realize high efficiency and low SAR value in both an unfolded state and a folded state.

In another aspect, an antenna is further provided, where the antenna includes a feed source, a first radiator, a second radiator, and a third radiator, where the first radiator, the second radiator, and the third radiator extend on a same straight line, the third radiator is located between the first radiator and the second radiator, and a length of the third radiator is smaller than lengths of the first radiator and the second radiator;

the first radiator is fed with an electric signal through the first feed point, the second radiator is fed with an electric signal through the second feed point, the first feed point is connected with the second feed point through the radio frequency connecting line, the third radiator is grounded, and the phases of the electric signals reaching the first feed point and the second feed point are in the same phase.

According to the antenna provided by the embodiment of the application, the first radiator and the second radiator are arranged on two sides of the third radiator, the phase difference of the electric signal reaching the first radiator and the phase difference of the electric signal reaching the second radiator are the same, a common mode of the linear antenna can be formed, and the effects of high efficiency, wide frequency and low SAR value are achieved.

In one possible embodiment, the first radiator and the second radiator are arranged in axial symmetry with respect to the third radiator, and the first feed point and the second feed point are arranged in axial symmetry with respect to the third radiator; the grounding point of the first radiator is positioned on one side of the first feeding point facing the third radiator, and the grounding point of the second radiator is positioned on one side of the second feeding point facing the third radiator.

The first radiator and the second radiator are arranged in axial symmetry relative to the third radiator so as to construct a common mode of the line antenna with the third radiator as a center, and the SAR value of the antenna can be reduced.

In one possible embodiment, a tuning inductance is connected to the third radiator, and the efficiency of the resonance generated by the third radiator is lower than the efficiency of the resonance generated by the first radiator and the second radiator.

The tuning inductance is arranged to reduce the efficiency of resonance generated by the third radiator, so that the third radiator can be prevented from influencing the resonance of the first radiator and the second radiator, and the influence on the common mode of the constructed linear antenna is avoided.

In another aspect, an embodiment of the present invention further provides an antenna, which includes a feed source, and a first radiator and a second radiator extending on the same straight line, where the first radiator feeds an electrical signal through a first feed point, the second radiator feeds an electrical signal through a second feed point, the first radiator and the second radiator have the same length and are arranged in a left-right direction, the first feed point is located at the same position on the first radiator as the second feed point is located on the second radiator, the first feed point and the second feed point are connected by a radio frequency connection line, and phases of the electrical signals reaching the first feed point and the second feed point are in a reverse phase.

According to the antenna provided by the embodiment of the application, the first radiator and the second radiator are identical in structure and arranged in a left-right mode, the phase difference of the electric signals reaching the first radiator and the second radiator is controlled to be opposite in phase, the common mode of the line antenna can be formed, and the effects of high efficiency, wide frequency and low SAR value are achieved.

In one possible embodiment, the grounding point of the first radiator is located on a side of the first feeding point facing the second radiator, and the grounding point of the second radiator is located on a side of the second feeding point facing away from the first radiator.

The grounding points on the first radiator and the second radiator are arranged on the same side of the respective feed points, so that the first radiator and the second radiator have the same structure and are arranged in a left-right manner.

In another aspect, an electronic device is further provided, and includes the antenna provided in the above embodiment.

According to the electronic device provided by the embodiment of the application, the symmetrical radiator structures are constructed on the non-foldable electronic device, and the phase difference of electric signals reaching the two radiators is controlled, so that the common mode of the line antenna is realized, and the high efficiency and the low SAR value of the antenna are realized.

The antenna and the foldable electronic device provided by the embodiment of the application utilize the space on two main bodies of the foldable electronic device to respectively set the radiators, the two radiators are connected through the radio frequency connecting line to form the distributed antenna, the phase difference of the radiator signals fed into two sides through the control feed source is used for realizing that the current presents reverse distribution on the radiators on two sides of the rotating shaft in the unfolding state, the common mode of the line antenna is constructed, the two radiators in the folding state form adjacent parallel radiators, and the current on the parallel radiators is distributed in the same direction, so that the high efficiency and the low SAR value of the antenna can be realized. In addition, compared with the case that the antennas are respectively arranged on the two main bodies of the foldable electronic device, the distributed antenna is arranged in the embodiment of the application, so that more resonant modes and bandwidths can be obtained.

Drawings

Fig. 1a is a schematic diagram of a common mode of a slot antenna according to an embodiment of the present application;

fig. 1b is a schematic diagram of a differential mode of a slot antenna according to an embodiment of the present application;

fig. 1c is a schematic diagram of a common mode of a line antenna according to an embodiment of the present application;

fig. 1d is a schematic diagram of a differential mode of a line antenna according to an embodiment of the present application;

fig. 2 is a schematic structural diagram of a foldable electronic device in an unfolded state and in a folded state according to an embodiment of the present application;

fig. 3 is a schematic structural diagram of an antenna according to an embodiment of the present application;

fig. 4a is a schematic structural diagram of an antenna according to an embodiment of the present application;

fig. 4b is a schematic structural diagram of another antenna provided in an embodiment of the present application;

fig. 4c is a schematic structural diagram of another antenna according to an embodiment of the present application;

fig. 5 is a schematic structural diagram of an antenna according to an embodiment of the present application;

fig. 6 is a return loss coefficient graph of a first antenna and a second antenna according to an embodiment of the present application;

fig. 7 is a graph illustrating the efficiency of a first antenna and a second antenna according to an embodiment of the present disclosure;

FIGS. 8a-8d are schematic heat-point diagrams of a first antenna;

FIGS. 9a-9d are schematic heat-point diagrams of a second antenna;

10a-10f are schematic heat-point diagrams of an antenna at a first resonant frequency at different phases;

11a-11f are schematic heat-point diagrams of an antenna at a second resonant frequency at different phases;

FIGS. 12 a-12 f are current profiles for antennas at different phases;

FIG. 13 is a graph comparing the current distribution of the antenna in the unfolded state and the folded state;

fig. 14 is a comparison graph of the radiation efficiency of the antenna of the electronic device in a folded state;

FIG. 15 is a comparison graph of system efficiency of an antenna of an electronic device in a folded state;

fig. 16 is a schematic structural diagram of an antenna according to an embodiment of the present application;

FIG. 17 is a graph of return loss coefficients for a first antenna and a second antenna;

FIG. 18 is a graph of the efficiency of the first antenna and the second antenna;

FIGS. 19 a-19 d are schematic heat-point diagrams of a second antenna;

FIGS. 20 a-20 f are schematic heat-point diagrams of an antenna at a first resonant frequency at different phases;

21 a-21 f are schematic heat-point diagrams of an antenna at a second resonant frequency at different phases;

FIGS. 22 a-22 f are current profiles for antennas at different phases;

fig. 23 is a schematic structural diagram of an antenna according to an embodiment of the present application;

FIG. 24 is a graph of return loss coefficients for a first antenna and a second antenna;

FIG. 25 is a graph of the efficiency of the first antenna and the second antenna;

FIGS. 26 a-26 d are schematic heat-point diagrams of a first antenna;

27 a-27 f are schematic heat-point diagrams of an antenna at a first resonant frequency at different phases;

28 a-28 f are schematic heat-point diagrams of the antenna at a second resonant frequency at different phases;

FIGS. 29 a-29 f are current profiles for antennas at different phases;

fig. 30 is a schematic structural diagram of a line antenna according to an embodiment of the present application;

FIG. 31 is a graph of return loss coefficients for the antenna provided in FIG. 30;

fig. 32 is a graph of the efficiency of the antenna provided in fig. 30;

FIGS. 33 a-33 b are current distribution diagrams of the antenna provided in FIG. 30;

34 a-34 d are schematic heat-point diagrams of a first antenna;

fig. 35 is a schematic structural diagram of an antenna according to an embodiment of the present application;

fig. 36 is a graph of the radiation efficiency of the antenna provided in fig. 35 at different phases;

fig. 37 is a graph of system efficiency for the antenna provided in fig. 35 at different phases;

FIGS. 38 a-38 b are graphs of the current distribution of the antenna in phase;

FIGS. 39 a-39 d are schematic heat spot diagrams of the antenna in phase;

fig. 40 is a simplified structural diagram of an antenna according to an embodiment of the present application;

fig. 41 is a schematic structural diagram of another antenna provided in an embodiment of the present application;

fig. 42 is a graph of the radiation efficiency of the antenna provided in fig. 41 at different phases;

fig. 43 is a graph of system efficiency for the antenna provided in fig. 41 at different phases;

FIGS. 44 a-44 b are graphs of the current distribution of the antenna in phase;

FIGS. 45 a-45 d are schematic heat-point diagrams of the antenna in phase;

FIGS. 46 a-46 b are graphs of the current distribution of the antenna in opposite phases;

FIGS. 47 a-47 d are schematic heat-point diagrams of the antenna in reverse phase;

fig. 48 is a simplified structural diagram of an antenna according to an embodiment of the present application;

fig. 49 is a schematic structural diagram of another antenna applied to a foldable electronic device according to an embodiment of the present application.

Description of reference numerals:

100-an electronic device; 11 a-a first body; 11 b-a second body; 12-a rotating shaft; 13-floor; 21-a first radiator; 211-a first slit; 212-a third gap; 22-a second radiator; 221-a second gap; 222-a fourth gap; 23-a feed source; 24-radio frequency connection lines; 25-a third radiator; f1 — first feed point; f2 — second feed point; SW1, SW2, SW3, SW 4-tuning switches; 31-a circuit board; 32-a radiator; 33-a feed source; 34-a feed line.

Detailed Description

Hereinafter, the technical terms mentioned in the embodiments of the present application are explained to facilitate understanding by those skilled in the art.

Return loss of the antenna: which may be understood as the ratio of the power of the signal reflected back to the antenna port via the antenna circuit to the transmitted power at the antenna port. The smaller the signal reflected back is, the larger the signal radiated to the space by the antenna is, and the greater the radiation efficiency of the antenna is. The larger the reflected signal is, the smaller the signal radiated to the space by the antenna is, and the radiation efficiency of the antenna is smaller. The return loss of the antenna can be represented by an S11 parameter, and the S11 parameter is usually negative. S11, the smaller the parameter is, the smaller the return loss of the antenna is, and the higher the system efficiency of the antenna is; the larger the S11 parameter is, the larger the return loss of the antenna is, and the lower the system efficiency of the antenna is.

Antenna isolation: refers to the ratio of the signal transmitted by one antenna and received by the other antenna to the signal of the transmitting antenna. Isolation is a physical quantity that measures the magnitude of mutual coupling between antennas. Assuming that the two antennas form a two-port network, the isolation between the two antennas is S21, S12 between the antennas. The antenna isolation can be represented by S21 and S12 parameters. The S21, S12 parameters are usually negative numbers. The smaller the parameters S21 and S12 are, the larger the isolation between the antennas is, and the smaller the mutual coupling degree of the antennas is; the larger the parameters S21 and S12 are, the smaller the isolation between the antennas is, and the larger the mutual coupling degree of the antennas is. The isolation of the antenna depends on the antenna radiation pattern, the spatial distance of the antenna, the antenna gain, etc. When the isolation of the antennas is less than-13 dB, the antennas can be considered to have good isolation.

Antenna system efficiency: refers to the ratio of the power radiated by the antenna into space (i.e., the power that effectively converts the portion of the electromagnetic wave) to the input power to the antenna.

Antenna radiation efficiency: refers to the ratio of the power radiated out of the antenna into space (i.e., the power that effectively converts the portion of the electromagnetic waves) to the real power input to the antenna. Where active power input to the antenna = input power-loss power of the antenna; the loss power mainly comprises return loss power and ohmic loss power and/or dielectric loss power of metal.

Common Mode (CM) Mode of slot antenna (also called slot antenna):

fig. 1a is a schematic diagram of a common mode of a slot antenna according to an embodiment of the present application. Referring to fig. 1a, the slot antenna may be formed by providing a hollowed-out slot or gap on the radiator, or the radiator and the ground (e.g., the floor/circuit board 31) may surround the slot or gap, for example, the slot or gap is formed by the structure of the radiator and the ground and/or the slot or gap is formed by the electrical connection between the radiator and the ground, or the slot or gap may be formed by slotting the floor, for example. In one embodiment, an opening is provided on one side of the slot, i.e. the radiator 32, and the feed 33 is connected to the opening. In another embodiment, the feed 33 may be connected within a predetermined length from the opening. Anti-symmetric feeding (anti-symmetric feeding) may be used at or near the opening of the radiator 32, where the positive and negative poles of the feeding unit 33 are respectively connected to two ends of the opening, and the positive and negative poles of the feeding unit 33 output signals with the same amplitude and opposite phases, for example, with a phase difference of 180 ° ± 10 °. At this time, the current appears asymmetrically distributed on the radiators on both sides of the opening, for example, the same direction distribution in fig. 1 a. It should be understood that references to "co-distributed" currents in this application do not refer to the direction of the currents being purely, in a single, same direction, but rather schematically indicate that the currents are substantially in a common direction on a single radiator or multiple radiators, e.g., the currents all flow from one side of the radiator to the other. A CM pattern based on a slot antenna in which current appears asymmetrically distributed on the radiator on both sides of the opening, or in which current appears isotropically distributed around the slot on the conductor around the slot may be referred to as a slot antenna.

Differential Mode (DM) Mode of slot antenna:

fig. 1b is a schematic diagram of a differential mode of a slot antenna according to an embodiment of the present application. In one embodiment, the feed source 33 is connected to the middle of the slot, and the middle of the radiator 32 may adopt symmetric feeding (symmetric feeding), where one end of the feed unit 33 is connected to the radiator and the other end is grounded, where the connection point (feed point) between the feed unit 33 and the radiator is located in the middle of the radiator. Reference herein to a "central location" of the radiator includes the center of the radiator, which may be, for example, the midpoint of the geometry, or the midpoint of the electrical length (or a region within a certain range around the midpoint). In one embodiment, the connection between the feeding unit 33 and the radiator covers the center of the radiator. At this time, the current is distributed around the slot on the conductor around the slot, and is symmetrically distributed on both sides of the middle position of the slot, for example, the current on both sides of the radiator 32 is reversely distributed in the figure. It should be understood that reference to "oppositely distributed" currents in this application does not mean that the direction of the current is purely, singly, in opposite directions, but rather indicates schematically that the current is directed substantially in opposite directions on a segment of the radiator or a segment of the radiator, e.g., the current flows from one point on the radiator to opposite sides of the radiator, respectively. A slot antenna mode based on the symmetrical distribution of current on both sides of the connection of the feed 33 and the radiator 32, or based on the symmetrical distribution of current around the slot, may be referred to as a DM mode of the slot antenna.

It is understood that the radiator of the slot antenna may be understood as a metal structure (e.g. comprising a part of the floor) generating radiation, which may comprise an opening, as shown in fig. 1a, or which may be a complete loop, as shown in fig. 1b, which may be adapted according to actual design or production needs. For example, for the CM mode of the slot antenna, a complete annular radiator may be used as shown in fig. 1b, for example, two feeding points are provided at the middle position of the radiator on one side of the slot, and anti-symmetric feeding is adopted (for example, signals with the same amplitude and opposite phases are respectively fed to the two ends where the opening position is originally provided), and similar effects to those of the antenna structure shown in fig. 1a can also be obtained. Accordingly, for the DM mode of the slot antenna, a radiator including an opening may be used as shown in fig. 1a, for example, a symmetric feeding manner is used at two ends of the opening (for example, the same feeding signal is fed to two ends of the radiator at two sides of the opening), and similar effects to those of the antenna structure shown in fig. 1b may also be obtained.

It should be understood that, in practical applications, the position of the feeding point of the slot antenna is not limited, and the position of the feeding point needs to be designed according to the requirement of the actual operating frequency band, and the positions of the feeding points in fig. 1a and 1b are only schematic. For a slot antenna, which may produce both CM mode resonance and DM mode resonance, adjusting the location of the feed point may affect the characteristics of both resonances.

It should be added that, for a slot antenna, its mode can also be defined according to the distribution of the electric field. In a slot antenna, the electric field is distributed in the slot from one side of the slot to the other. The electric fields are reversely distributed on two sides of the middle position of the slot to form a CM mode of the slot antenna; the electric field is distributed in the same direction at two sides of the middle position of the slot, and the DM mode of the slot antenna is formed.

Common mode of wire antenna (wire antenna): fig. 1c is a schematic diagram of a common mode of a line antenna according to an embodiment of the present application. Referring to fig. 1c, in an embodiment, the radiator 32 of the line antenna is connected to the feed 33 through the feed line 34, the connection position of the feed line 34 and the radiator 32 may be located in the middle of the radiator 32, and the current on the radiator 32 is distributed symmetrically, for example, reversely in the figure, on both sides of the middle position. A line antenna pattern based on which a current appears symmetrically distributed on both sides where the radiator 32 is connected to the feed line 34 may be referred to as a CM pattern of the line antenna.

Differential mode of the line antenna: fig. 1d is a schematic diagram of a differential mode of a line antenna according to an embodiment of the present application. Referring to fig. 1d, the radiator 32 of the line antenna is connected to the feed 33 by a feed line 34, the connection position of the feed line 34 and the radiator 32 may be located in the middle of the radiator 32, and the current on the radiator 32 exhibits a non-symmetrical distribution, such as a homodromous distribution in the figure, on both sides of the middle position. A line antenna mode based on the asymmetric distribution of current on both sides of the connection of the radiator 32 and the feed line 34 may be referred to as a DM mode of the line antenna.

It should be understood that, for the radiator 32 of the line antenna, it can be understood as a metal structure that generates radiation, both ends of the metal structure are open ends, and the position of the feeding point on the radiator 32 is not limited, and the feeding point may be disposed at a middle position on the radiator 32 as shown in fig. 1c and 1d, or may be disposed in a region close to the middle position or other positions, and the position of the feeding point needs to be designed according to the requirements of the actual operating frequency band. The number of radiators 32 of the line antenna may be one piece, as shown in fig. 1c, or may be two pieces, as shown in fig. 1d, and may be adjusted according to actual design or production requirements. For example, for the CM mode of the line antenna, two radiators may be used as shown in fig. 1d, and two ends of the two radiators are disposed opposite to each other and separated by a gap, so that an effect similar to the antenna structure shown in fig. 1c can be obtained. Accordingly, for the DM mode of the line antenna, it is also possible to use a radiator as shown in fig. 1c, for example, two feeding points are disposed in the middle of the radiator and an anti-symmetric feeding manner is adopted (for example, two symmetrical feeding points on the radiator feed signals with the same amplitude and opposite phases), and the similar effect as the antenna structure shown in fig. 1d can also be obtained. The line antenna may further include a T-type line antenna, where the T-type line antenna refers to a line antenna having a normal connection point on a radiator, and the normal connection point is equivalent to incorporating an inductor, that is, the structure does not necessarily need to be provided with a ground, and the same effect may be achieved by incorporating an inductor.

It should be added that, in practical applications, for a line antenna, it may generate the resonance of the CM mode and the resonance of the DM mode at the same time, and adjusting the position of the feeding point may affect the characteristics of the two resonances.

Along with the continuous improvement of living standard of people, the screen display effect of electronic equipment such as cell-phone has more and more received attention, for having realized great screen area on the electronic equipment of less volume, electronic equipment can adopt foldable structure. The foldable electronic device may have two bodies that can be relatively rotated and folded about a rotation axis so that the foldable electronic device has both unfolded and folded states. The antenna of the foldable electronic device is difficult to design, on one hand, in a folded state, the foldable electronic device lacks a usable side edge compared with the conventional electronic device, namely, the arrangement space of the antenna is limited; on the other hand, switching between the unfolded state and the folded state causes a change in the state of the antenna, resulting in a large change in antenna performance, such as a drop in antenna performance from the unfolded state to the folded state.

In a related art, a main radiator and a standby parasitic branch may be respectively disposed on two main bodies of a foldable electronic device, when the foldable electronic device is in an unfolded state, the standby parasitic branch is far away from the main radiator, the main radiator implements an antenna function, when the foldable electronic device is in a folded state, the main radiator and the standby parasitic branch are close to each other, and the main radiator and the standby parasitic branch implement the antenna function through coupling radiation. Such a design does not make good use of the space of the foldable electronic device in the unfolded state and the antenna performance in the unfolded state may be degraded.

In another related art, a main radiator and an auxiliary radiator may be respectively disposed on two bodies of a foldable electronic device, the main radiator and the auxiliary radiator are connected by a radio frequency connection line, when the foldable electronic device is in an unfolded state, the radio frequency connection line connects the main radiator and the auxiliary radiator to realize an antenna function by radiating together, when the foldable electronic device is in a folded state, the main radiator and the auxiliary radiator are close to each other, and the radio frequency connection line may be disconnected to allow the auxiliary radiator to be parasitic by coupling of the main radiator and radiate together with the main radiator to realize the antenna function. This design makes good use of space when the foldable electronic device is in the unfolded state, but feeding through the coupling in the folded state may result in a reduced efficiency of the antenna and/or in an increased Specific Absorption Rate (SAR) value.

The SAR value of an antenna is a regulation, and organizations such as the European Community (CE) and the Federal Communications Commission (FCC) have strict regulations on the SAR value of an antenna of an electronic device. The rule of the SAR value can directly influence the nonlinear energy of a user when the user actually uses the electronic equipment, the form of some antennas has a higher SAR value, and the device has power rollback when the SAR value does not exceed the rule in actual use, so that the wireless performance is reduced, and the actual experience of the user is directly influenced. Therefore, how to obtain a higher antenna performance and a lower SAR value and reduce power back-off by optimizing the antenna design under the condition that the size and the space of the radiator structure of the electronic device are limited is an urgent task in the antenna design of the electronic device at present.

Based on the above problem, embodiments of the present application provide an antenna and a foldable electronic device, where radiators are respectively disposed in two main bodies of the foldable electronic device, the two radiators are connected by a radio frequency connection line to form a distributed antenna, and a phase difference between signals fed into radiators on two sides by a control feed source is used to realize that current appears in symmetric distribution on the radiators on two sides of a rotating shaft in an unfolded state, and two radiators form adjacent parallel radiators in a folded state, and the currents on the parallel radiators are distributed in the same direction, so that high efficiency and low SAR value of the antenna can be realized.

Example one

The embodiment of the application provides a foldable electronic device, including but not limited to a mobile phone, a tablet computer, a notebook computer, a display, a vehicle-mounted device and other terminal devices with a display screen. The embodiment of the present application does not specifically limit the specific form of the foldable electronic device. The folding times of the foldable electronic device may be one time, two times or more, and for convenience of understanding, the specific structure of the foldable electronic device is specifically described in the embodiment of the present application with a foldable mobile phone that is folded once.

Fig. 2 is a schematic structural diagram of a foldable electronic device in an unfolded state and in a folded state according to an embodiment of the present application. Referring to fig. 2, the foldable electronic device 100 includes a first body 11a and a second body 11b, and the first body 11a and the second body 11b can rotate about a rotation axis 12 therebetween, so that ends of the first body 11a and the second body 11b far from the rotation axis 12 are relatively close to or relatively far from each other.

In the embodiment of the present application, the side of the electronic device 100 having the flexible screen may be defined as a front side, and the other side opposite to the flexible screen may be defined as a back side. The foldable electronic device 100 may adopt a fold-in type folding structure, that is, the electronic device 100 is folded toward a side having a flexible screen, at least one of the first body 11a and the second body 11b is rotated as indicated by an arrow in the figure, and the flexible screen is located inside the electronic device 100 after the folding. It will be understood that the foldable electronic device 100 may also be of a fold-out type, i.e. the electronic device 100 is folded towards the back side, and the flexible screen is located outside the electronic device 100 after folding.

The first body 11a and the second body 11b may be implemented in a form including a middle frame, a rear case, a middle plate, and the like of the electronic apparatus 100. The first body 11a and the second body 11b may be made of metal, plastic, ceramic, glass, etc., and have high structural strength to support the flexible screen. The first body 11a and the second body 11b may further be connected to a main board, a battery, a camera module, and other structures, and for convenience of description, in this embodiment, the main board is disposed in the first body 11a, the left first body 11a is used as a main screen, and the right second body 11b is used as a sub screen.

In addition, for convenience of illustration, taking the electronic device 100 in the unfolded state as an example, when the user views the display surface, the rotating shaft 12 is located in the middle of the left main screen and the right sub-screen, the upper side and the lower side of the display surface may be defined as the top and the bottom of the electronic device 100, respectively, and four frames located on the upper side, the lower side, the left side and the right side of the display surface may be located as a top frame, a bottom frame, a left frame and a right frame, respectively. It should be understood that the shaft 12 is parallel to the left and right frames and perpendicular to the top and bottom frames, the top frame may include two sections located at the left and right sides of the shaft 12, and the bottom frame may include two ends located at the two sides of the shaft 12.

The antenna provided by the present application is described in detail below with reference to the drawings and specific embodiments.

Fig. 3 is a schematic structural diagram of an antenna according to an embodiment of the present application, which may be regarded as a partial structural diagram of a bottom of the electronic device 100 in fig. 1. Referring to fig. 3, an antenna provided in an embodiment of the present application may include a feed 23, a radio frequency connection line 24, a first radiator 21 disposed in a first body 11a, and a second radiator 22 disposed in a second body 11 b.

The feed source 23 is used to feed the first radiator 21 and the second radiator 22, and the position of the feed source 23 is not particularly limited, and may be set in the first body 11a or the second body 11b, for example. In the embodiment of the present application, the feed 23 may be disposed in the first body 11a and electrically connected to the main board of the first body 11 a.

The present application does not limit the manufacturing process of the first radiator 21 and the second radiator 22. For example, the first radiator 21 and the second radiator 22 may be made of a metal frame of an electronic device, a Flexible Printed Circuit (FPC), a laser, or a spray coating process. For convenience of illustration, in the drawings of the embodiments of the present application, the first radiator 21 and the second radiator 22 are illustrated as being made of metal frames of the electronic device 100.

The lengths and specific positions of the first radiator 21 and the second radiator 22 are not particularly limited in the embodiment of the present application, the first radiator 21 and the second radiator 22 may be disposed on a bottom frame or a top frame of the electronic device 100, and the first radiator 21 may extend to a left frame and the second radiator 22 may extend to a right frame. For convenience of description, in the following drawings, the first radiator 21 and the second radiator 22 are disposed on the bottom bezel of the electronic device 100 as an example.

It should be understood that the main board of the electronic device 100 is provided with a grounding area, and the middle board, the middle board and the rotating shaft 12 of the electronic device 100 are all grounded. In a possible embodiment, both ends of the first radiator 21 and both ends of the second radiator 22 may be grounded through the floor 13. In another possible embodiment, the first radiator 21, the second radiator 22 and the rotating shaft 12 overlap at least partially in length in the extending direction of the bottom frame, one end of the first radiator 21 close to the rotating shaft 12 may be grounded through the rotating shaft 12, and the other end may be grounded through the floor 13, and one end of the second radiator 22 close to the rotating shaft 12 may be grounded through the rotating shaft 12, and the other end may be grounded through the floor 13. The first radiator 21 and the second radiator 22 are grounded by using the rotating shaft 12, so that the structure can be more compact and the space utilization rate can be improved. In a possible embodiment, the width of the shaft 12 may be in the range of 20mm to 50mm, for example, less than 30mm, and the distance between the first radiator 21 and the second radiator 22 may be less than 30mm.

It should be understood that there is a gap between the first radiator 21 and the floor 13, and both ends of the first radiator 21 are grounded, that is, a slot is formed by the electrical connection between the first radiator 21 and the ground, and the first radiator 21 and the ground can be regarded as forming a slot antenna; similarly, a gap is formed between the second radiator 22 and the floor 13, and two ends of the second radiator 21 are grounded, that is, a slot is formed by electrically connecting the second radiator 22 and the ground, and an electrical signal is fed to the second radiator 22, and the second radiator 22 and the ground can be regarded as forming a slot antenna. The gap width between the first radiator 21 and the floor 13 and between the second radiator 22 and the floor 13 is not particularly limited in the embodiment of the present application, and for example, the gap width may be less than 2mm.

The first radiator 21 may be provided with a first slot 211, the second radiator 22 may be provided with a second slot 221, and the first slot 211 and the second slot 221 may be formed by providing a broken slot on a metal frame and filling an insulating plastic material in the broken slot. After the first radiator 21 having the first slot 211 is fed with the electrical signal, two radiator segments of the first radiator 21 separated by the first slot 211 may be respectively used as the main feed branch and the coupling parasitic branch, and respectively form the CM mode of the slot antenna and the DM mode of the slot antenna, and the second radiator 22 is the same and will not be described again.

In this embodiment, the first radiator 21 may receive the electrical signal input by the feed 23 through the first feed point F1, the second radiator 22 may receive the electrical signal input by the feed 23 through the second feed point F2, and the first feed point F1 and the second feed point F2 may be connected through the radio frequency connection line 24, so that the first radiator 21 and the second radiator 22 form a distributed antenna. When the foldable electronic device 100 is switched between the unfolded state and the folded state, the first radiator 21 and the second radiator 22 are always connected by the rf connection line 24, and are used as an integral antenna. At this time, the current distribution on the first radiator 21 and the second radiator 22 is affected by the phase difference of the signals reaching the first feeding point F1 and the second feeding point F2, and cannot be regarded as the slot antenna alone. The first feeding point F1 may be disposed on the left or right side of the first slot 211 as shown by the area encircled by the dashed line on the first radiator 21, and the second feeding point F2 may be disposed on the left or right side of the second slot 221 as shown by the area encircled by the dashed line on the second radiator 22. It is understood that the positions of the first feeding point F1 and the second feeding point F2 are designed with the left and right sides of the slot 221, with four basic combinations, thereby forming at least three antennas with different structures.

Fig. 4a is a schematic structural diagram of an antenna according to an embodiment of the present application. Referring to fig. 4a, in the first form, the first feeding point F1 may be disposed at a side of the first slot 211 facing the second slot 221, i.e., a right side of the first slot 211, and the second feeding point F2 may be disposed at a side of the second slot 221 facing the first slot 211, i.e., a left side of the second slot 221. When the electronic device 100 is in the unfolded state, the radiator connected to the first feeding point F1 and located between the first slot 211 and the rotating shaft 12 forms a main feeding branch, and the radiator on the other side of the first slot 211 forms a coupling parasitic branch; the radiator located between the second slot 221 and the rotating shaft 12 and connected to the second feeding point F2 forms a main feeding branch, and the radiator on the other side of the second slot 221 forms a coupling parasitic branch. The opening direction of the tail end of the main feed branch of the first radiator 21 is leftward, the opening direction of the tail end of the main feed branch of the second radiator 22 is rightward, and the opening directions of the tail ends of the two main feed branches are opposite.

Fig. 4b is a schematic structural diagram of another antenna according to an embodiment of the present application. Referring to fig. 4b, in the second form, the first feeding point F1 may be disposed at a side of the first slot 211 facing away from the second slot 221, i.e., at a left side of the first slot 211, and the second feeding point F2 may be disposed at a side of the second slot 221 facing the first slot 211, i.e., at a left side of the second slot 221. At this time, the opening direction of the end of the main feed branch of the first radiator 21 is rightward, the opening direction of the end of the main feed branch of the second radiator 22 is rightward, and the opening directions of the ends of the two main feed branches are the same.

In the third form, the first feeding point F1 may be disposed on a side of the first slot 211 facing the second slot 221, i.e., on the right side of the first slot 211, and the second feeding point F2 may be disposed on a side of the second slot 221 facing away from the first slot 211, i.e., on the right side of the second slot 221. At this time, the opening direction of the end of the main feed branch of the first radiator 21 is leftward, the opening direction of the end of the main feed branch of the second radiator 22 is leftward, and the opening directions of the ends of the two main feed branches are the same. It is to be understood that the antenna structure in the third form and the antenna structure in the second form may be regarded as the same, and therefore, the embodiments of the present application are described in detail below only by taking the antenna structure in the second form as an example.

Fig. 4c is a schematic structural diagram of another antenna according to an embodiment of the present application. The first feeding point F1 may be disposed at a side of the first slot 211 facing away from the second slot 221, i.e., at a left side of the first slot 211, and the second feeding point F2 may be disposed at a side of the second slot 221 facing away from the first slot 211, i.e., at a right side of the second slot 221. The opening direction of the tail end of the main feed branch of the first radiator 21 is rightward, the opening direction of the tail end of the main feed branch of the second radiator 22 is leftward, and the opening directions of the tail ends of the two main feed branches are opposite.

The first radiator 21 and the second radiator 22 function as distributed antennas when the electronic device is in the unfolded state, and the first radiator 21 and the second radiator 22 are disposed in parallel and close to each other when the electronic device is in the folded state. It is understood that after the electronic device is folded, the first body 11a and the second body 11b may not be completely attached, and there may be a gap on a side close to the rotation axis 12, so that after the electronic device is folded, the first radiator 21 and the second radiator 22 may have a smaller included angle instead of being strictly parallel to each other, and the first radiator 21 and the second radiator 22 may not be completely overlapped but have a certain error in a thickness direction of the electronic device. It should be understood that the reference to "parallel" in this application does not mean that the directions of extension of the first radiator 21 and the second radiator 22 are strictly parallel to each other, but rather that the first radiator 21 and the second radiator 22 are allowed to have a small included angle, for example less than 5 °, which can be considered substantially parallel.

The idea of the embodiment of the application is that by controlling the phase difference of the electrical signal reaching the first radiator 21 and the second radiator 22, when the electronic device is in the unfolded state, the current is symmetrically distributed on the radiators on the two sides of the rotating shaft, and simultaneously, when the electronic device is in the folded state, the current directions on the parallel first radiator 21 and the parallel second radiator 22 are kept consistent, so as to achieve the effects of high efficiency and low SAR. It should be understood that the direction of the current flow on the first radiator 21 and the second radiator 22 remains the same, and does not mean that the direction of the current flow is purely and unidirectionally the same, but rather schematically indicates that the current flow is substantially in a common direction on both sections of the radiator, e.g. the current flow is from one side of the radiator to the other.

The following describes the principle and effect of reducing the SAR value of an antenna by controlling the phase difference between the electrical signal and the first radiator 21 and the second radiator 22 according to three scenarios and a more specific embodiment with reference to the three antenna structures shown in fig. 4a, 4b, and 4 c.

Scene one

Fig. 5 is a schematic structural diagram of an antenna according to an embodiment of the present application. Referring to fig. 5, in the embodiment of the present invention, metal frames located at two sides of the rotating shaft 12 may be respectively used as the first radiator 21 and the second radiator 22, and an insulating plastic medium is filled between an inner surface of the metal frame and a middle frame of the electronic device. In one embodiment, the dielectric has a relative dielectric constant of 3.0 and a tangent loss angle of 0.01.

A first slit 211 and a third slit 212 are arranged on the metal frame located in the first main body 11a, the metal frame between the third slit 212 and the rotating shaft 12 can be regarded as a first radiating body 21, and the first slit 211 divides the first radiating body 21 into two branches; the metal frame located in the second body 11b is provided with a second gap 221 and a fourth gap 222, the metal frame between the fourth gap 222 and the rotating shaft 12 can be regarded as the second radiator 22, and the second gap 221 divides the second radiator 22 into two branches.

One end of the first radiator 21 close to the rotating shaft 12 is grounded through the rotating shaft 12, one end of the second radiator 22 close to the rotating shaft 12 is grounded through the rotating shaft 12, the first feeding point F1 feeds power to the branch on the right side of the first slot 211, and the second feeding point F2 feeds power to the branch on the left side of the second slot 221, that is, the opening direction of the tail end of the main feeding branch of the first radiator 21 is leftward, the opening direction of the tail end of the main feeding branch of the second radiator 22 is rightward, and the opening directions of the tail ends of the two main feeding branches are opposite.

In a specific embodiment, when the electronic device is in the unfolded state, the width of the hinge 12 may be set to 30mm, and the widths of the first slit 211, the third slit 213, the second slit 221, and the fourth slit 222 may be 1.5mm.

In addition, tuning switches SW1 and SW3 may be respectively disposed on the main feed branch and the coupling parasitic branch of the first radiator 21, and tuning switches SW2 and SW4 may be respectively disposed on the main feed branch and the coupling parasitic branch of the second radiator 22 to adjust the resonant frequency.

When the electronic device is in the unfolded state, if the first radiator 21 and the second radiator 22 are not connected by using the radio frequency connection line, but the electrical signal is fed to the first radiator 21 alone, the first radiator 21 and the ground may form a first antenna, which is a slot antenna, and similarly, the electrical signal is fed to the second radiator 22 alone, and the second radiator 22 and the ground may form a second antenna, which is a slot antenna.

Fig. 6 is a return loss coefficient graph of the first antenna and the second antenna according to an embodiment of the present application, where S11 and S22 represent return loss characteristics of the first antenna and the second antenna, respectively, and S12 represents isolation of the first antenna and the second antenna. Fig. 7 is a graph illustrating efficiency of a first antenna and a second antenna according to an embodiment of the present application, where E1 and E2 represent system efficiency of the first antenna and the second antenna, respectively, and R1 and R2 represent radiation efficiency of the first antenna and the second antenna, respectively. Referring to fig. 6 and 7, when the first antenna and the second antenna are respectively fed with the electric signals, the first antenna and the second antenna have equivalent performance, two resonances are generated, and two center resonance frequencies of the two antennas coincide, the first resonance frequency is 1.83GHz, and the second resonance frequency is 2.61GHz. And the isolation between the first antenna and the second antenna is less than-13 dB, and the first antenna and the second antenna have good isolation.

The SAR value results of the first antenna are shown in table 1 and the SAR value results of the second antenna are shown in table 2 by simulating the 5mm body SAR values (averaged by 10 g) of the first antenna and the second antenna on the back surface (Bottomside) and the bottom surface (Backside) of the electronic device and normalizing according to-5 dB efficiency. It should be added that the simulation surface of the SAR value of the present application is set according to the position where the radiator is set, and the radiator is set on the bottom frame of the electronic device, so as to simulate the back surface and the bottom surface, and if the radiator is set on the top frame of the electronic device, the back surface and the top surface can be simulated.

TABLE 1

TABLE 2

In the embodiment of the application, the normalized SAR is considered to belong to high SAR when the normalized SAR is higher than 1.0W/Kg. Referring to tables 1 and 2, it can be seen that the SAR values of the first antenna and the second antenna are high, and especially the normalized SAR value of the first antenna at a resonant frequency of 2.61GHz can reach 1.70W/Kg, which is a high SAR.

Fig. 8a-8d are schematic heat point diagrams of a first antenna, where fig. 8a and 8b are first resonances, fig. 8c and 8d are second resonances, fig. 8a and 8c are back surfaces, and fig. 8b and 8d are bottom surfaces. Referring to fig. 8a-8d, for the first antenna, the hot spot of the first resonance is concentrated at the main feed stub, the hot spot of the second resonance is concentrated at the coupling parasitic stub, and the hot spot of the second resonance is higher.

Fig. 9a-9d are schematic heat-point diagrams of a second antenna, where fig. 9a and 9b are first resonances, fig. 9c and 9d are second resonances, fig. 9a and 9c are rear surfaces, and fig. 9b and 9d are bottom surfaces. Referring to fig. 9a-9d, for the second antenna, the hot spots of the first resonance are relatively dispersed at the back surface and concentrated at the main feed branch at the bottom surface, and the hot spots of the second resonance are concentrated at the main feed branch at the back surface and are very dispersed at the bottom surface.

It should be noted that, in the hot spot diagram, a line outlines a local structure of the electronic device, the overall background is black, and an area close to an oval and white in color is surrounded by an area with a concentrated hot spot. The lower the degree of whitening of the area or the lighter the color of the center, the lower the concentration degree of the hot spots; the higher the degree of whitening of the area or the darker the color of the center, the higher the degree of hot spot concentration.

In this embodiment, the first antenna and the second antenna may be connected by a radio frequency connection line 24 to serve as a distributed antenna, wherein the feed 23 is disposed on the first body 11a, the feed 23 inputs an electrical signal for the first radiator 21 through the first feeding point F1, and inputs an electrical signal for the second radiator 22 through the radio frequency connection line 24 and the second feeding point F2, and the two electrical signals are distributed with equal power. It should be understood that the first radiator 21 and the second radiator 22 are fed with electrical signals through the same feed 23, and the two electrical signals have the same amplitude or are close to the same within a certain error range, which may be regarded as equal power distribution.

The radio frequency connection line 24 may be a Cable line or a Flexible Printed Circuit (FPC) or the like. The phase difference of the electric signal reaching the first feeding point F1 and the second feeding point F2 can be controlled by controlling the length of the radio frequency connection line 24.

In another possible embodiment, the phase difference of the electrical signals arriving at the first feeding point F1 and the second feeding point F2 can also be controlled by adding a phase shifter or the like to the radio frequency connection line 24, which enables the phase of the wave to be adjusted. The position of the phase shifter is not particularly limited, and may be provided in the first body 11a or the second body 11b, for example.

The electrical signals are controlled to reach the first radiator 21 and the second radiator 22 for phase difference to simulate the SAR value and the hot spot distribution of the antenna under different phase differences, which may have three cases of in-phase, 90 ° out of phase, and opposite phase, respectively, and the SAR value results of the antenna may be obtained as shown in tables 3a, 3b, and 3c, respectively.

It should be noted that "in phase", "90 °" and "reverse phase" provided in the embodiments of the present application are not fixed to the numerical value of the phase difference, and actually, the phase difference may be limited to a range, for example, the range of the phase difference may be 0 ± 10 ° in "in phase", "90 °" and "180 ° ± 10 ° in" reverse phase ".

TABLE 3a same phase

TABLE 3b phase difference of 90 °

TABLE 3c antiphase

Referring to tables 3a to 3c, it can be seen that, in terms of simulation efficiency, efficiency of the opposite phase is higher than efficiency of the same phase differing by 90 °. In terms of SAR value, for the first resonance, the normalized SAR value under the same phase belongs to high SAR, the SAR value under the phase difference of 90 degrees is lower, and the SAR value under the opposite phase is lower than 1W/Kg and belongs to low SAR. For the second resonance, SAR values are lower than 1W/Kg in three phases, and the low SAR is achieved. Since the first resonance can be regarded as the CM mode of the slot antenna, the SAR value is high, and the present application aims mainly to reduce the SAR value of the first resonance, so that overall, the SAR value in the opposite phase is lower than the SAR value in the same phase by 90 °, especially for the first resonance.

Comparing the SAR value of the distributed antenna with the SAR values of the single antennas each fed with the electric signal, it can be found that the first resonant SAR value of the distributed antenna is higher than that of the single antenna when the electric signals reaching the first radiator 21 and the second radiator 22 are in phase. When the electrical signals reaching the first radiator 21 and the second radiator 22 are in opposite phases, the SAR value of the distributed antenna is significantly lower than that of a single antenna, and therefore, the purpose of reducing the SAR value can be achieved by setting the distributed antenna and controlling the phase difference of the electrical signals reaching the first radiator 21 and the second radiator 22.

Fig. 10a-10f are schematic heat point diagrams of the antenna at a first resonance frequency with different phases, wherein fig. 10a-10 c are back, fig. 10 d-10 f are bottom, fig. 10a and 10d are in phase, fig. 10b and 10e are 90 ° out of phase, and fig. 10c and 10f are opposite phases. Referring to fig. 10a-10f, in the first resonance, the back and bottom hot spots of the antenna are gradually dispersed from the same phase to the opposite phase, i.e. the SAR value is gradually decreased.

Fig. 11a-11f are schematic heat point diagrams of an antenna at a second resonance frequency with different phases, wherein fig. 11a-11 c are back, fig. 11 d-11 f are bottom, fig. 11a and 11d are in phase, fig. 11b and 11e are 90 ° out of phase, and fig. 11c and 11f are opposite phases. Referring to fig. 11a-11f, it can be seen that at the second resonance, from the same phase to the opposite phase, the back and bottom hot spots of the antenna are always dispersed, and the SAR value is always lower because the radiation branches are dispersed at both ends.

Fig. 12a to 12f are current distribution diagrams of antennas at different phases, where fig. 12a and 12b are in phase, fig. 12c and 12d are 90 ° out of phase, fig. 12e and 12f are in opposite phase, fig. 12a, 12c and 12e are first resonances, and fig. 12b, 12d and 12f are second resonances. Referring to fig. 12a, the current on the first radiator 21 is distributed in the same direction, which may be regarded as a CM pattern of the slot antenna, and the current on the second radiator 22 is distributed in the same direction, which may be regarded as a CM pattern of the slot antenna. The currents on the first radiator 21 and the second radiator 22 are distributed in the same direction, and may be regarded as a DM mode of the line antenna. That is, in the first resonance, when the electric signals reaching the first radiator and the second radiator are in phase, the common mode of the slot antenna on the one side can be converted into the differential mode of the line antenna centered on the rotation axis 12 in the distributed antenna.

Referring to fig. 12b, the current on the first radiator 21 is reversely distributed, which can be regarded as a DM mode of the slot antenna, and the current on the second radiator 22 is reversely distributed, which can be regarded as a DM mode of the slot antenna. The currents on the first radiator 21 and the second radiator 22 are distributed in the same direction, and may be regarded as a DM mode of the line antenna. As for the main feed branch with stronger current, the current on the main feed branch of the first radiator 21 and the main feed branch of the second radiator 22 are distributed in the same direction, and may be regarded as a DM mode of the antenna. That is, in the second resonance, when the electric signals reaching the first radiator and the second radiator are in phase, the differential mode of the slot antenna on one side can be converted into the differential mode of the line antenna centered on the rotation axis 12 in the distributed antenna.

Referring to fig. 12c, the current on the first radiator 21 is distributed in the same direction, which may be regarded as a CM pattern of the slot antenna, and the current on the second radiator 22 is distributed in the same direction, which may be regarded as a CM pattern of the slot antenna. The currents on the first radiator 21 and the second radiator 22 are distributed in the same direction, and may be regarded as a DM mode of the line antenna. Referring to fig. 12d, the current on the first radiator 21 is reversely distributed, which can be regarded as a DM mode of the slot antenna, and the current on the second radiator 22 is reversely distributed, which can be regarded as a DM mode of the slot antenna. The currents on the first radiator 21 and the second radiator 22 are distributed in the same direction, and may be regarded as a DM mode of the line antenna. That is, when the electric signals reaching the first radiator and the second radiator are different by 90 °, the common mode and the differential mode of the slot antenna on the one side can be converted into the differential mode of the antenna centered on the rotation axis 12 in the distributed antenna. Compared to the solutions of fig. 12a and 12b, the mode of the differential mode or common mode of the antenna is the same, with the difference being the magnitude of the currents on both sides.

Referring to fig. 12e, the current on the first radiator 21 is distributed in the same direction, which may be regarded as a CM pattern of the slot antenna, and the current on the second radiator 22 is distributed in the same direction, which may be regarded as a CM pattern of the slot antenna. And the current on the first radiator 21 and the second radiator 22 are reversely distributed, which can be regarded as a CM pattern of the line antenna. That is, in the first resonance, when the electric signals reaching the first radiator and the second radiator are in opposite phases, the common mode of the slot antenna on one side can be converted into the common mode of the line antenna centered on the rotation axis 12 in the distributed antenna. Referring to fig. 12f, the current of the main feed branch of the first radiator 21 and the current of the main feed branch of the second radiator 22 are distributed in opposite directions, that is, in the second resonance, when the electrical signals reaching the first radiator and the second radiator are in opposite phases, the differential mode of the slot antenna on one side may be converted into the common mode of the line antenna centering on the rotation axis 12 in the distributed antenna.

It should be added that "taking the rotation axis as the center" means that the currents on both sides of the rotation axis 12 are distributed in the same direction or in opposite directions by taking the rotation axis 12 as the boundary, and in the embodiment of the present application, the structures of the first radiator 21 and the second radiator 22 can be regarded as axisymmetric including the symmetry of the positions of the slot, the grounding point, and the feeding point.

In short, in the electronic device in the unfolded state, when the directions of the openings at the ends of the main feed branches of the first radiator and the second radiator are opposite, the phase difference of the electric signal reaching the first radiator and the second radiator is controlled to be opposite, so that a common mode of the line antenna can be formed, and a distributed antenna with high performance, wide frequency and low SAR can be obtained. It is understood that the larger the range of resonant frequencies, i.e. the wider the bandwidth, where the system efficiency is above-5 dB, the more efficient the present embodiment brings the effect of wide frequency.

Fig. 13 is a comparison of the current distribution of the antenna in the unfolded state and the folded state, and fig. 13 is an example of fig. 12 e. Referring to fig. 13, when the current of the distributed antenna in the unfolded state can be distributed in an axisymmetric manner with the rotation axis 12 as an axis, after the antenna is folded, the first radiator 21 and the second radiator 22 are disposed in parallel and adjacent to each other, and the current distribution on the first radiator 21 and the second radiator 22 is in the same direction, so that the influence of the radiation branches on each other is minimized, and the antenna in the folded state has excellent efficiency.

Fig. 14 is a graph comparing radiation efficiency of an antenna of an electronic apparatus in a folded state, and fig. 15 is a graph comparing system efficiency of the antenna of the electronic apparatus in the folded state, in which C1 represents the same phase, C2 represents a phase difference of 90 °, and C3 represents an opposite phase. Referring to fig. 14 and 15, the radiation efficiency of the antenna with the phase difference of 90 ° and the radiation efficiency of the antenna with the opposite phase are not much different, and are both significantly greater than the radiation efficiency of the antenna with the same phase; the system efficiency of the antenna under the opposite phase is higher than that under the phase difference of 90 degrees and the same phase. Therefore, when the opening directions of the ends of the main feed branches of the first radiator 21 and the second radiator 22 are opposite, the phase difference between the electric signals reaching the first radiator 21 and the second radiator 22 is controlled to be opposite, so that the antenna in the folded state has excellent efficiency.

When the opening directions of the ends of the main feed branches of the first radiator 21 and the second radiator 22 are opposite, the phase difference of the electric signal reaching the first radiator 21 and the second radiator 22 is controlled to be opposite, 5mm body SAR values of the back surface and the bottom surface of the electronic device in a folded state are simulated, and the SAR value results of the antenna can be obtained according to-5 dB efficiency normalization, as shown in table 4a. Using only the 5mm body SAR values of the back and bottom surfaces of the first antenna on the first body 11a in the simulated folded state, normalized by-5 dB efficiency, the SAR value results for the antenna can be obtained as shown in table 4b.

TABLE 4a

TABLE 4b

As can be seen from comparing table 4a and table 4b, in the folded state, the SAR value of the distributed antenna provided in the embodiment of the present application is lower than that of the single antenna on the first body as a whole.

To sum up, the embodiment of the present application provides an antenna applied to a foldable electronic device, where a first radiator disposed on a first body and a second radiator disposed on a second body form a distributed antenna, and when the opening directions of the ends of main feed branches of the first radiator and the second radiator are opposite, a phase difference from an electric signal to the first radiator and the second radiator is controlled to be an opposite phase, so that when the electronic device is in an unfolded state, a common mode of a line antenna can be formed, and effects of high efficiency, wide frequency, and low SAR value are achieved; meanwhile, when the electronic device is in a folded state, because the current directions of the adjacent parallel radiation branches on the first main body and the second main body are kept consistent, high efficiency and low SAR value can be realized.

Scene two

Fig. 16 is another structural diagram of the antenna. Referring to fig. 16, in the embodiment of the present application, the first radiator 21, the second radiator 22, and the four slots may refer to the structure in fig. 5 in the first scenario, and details are not repeated here.

In this embodiment, the first feeding point F1 feeds power to the branch on the left side of the first slot 211, and the second feeding point F2 feeds power to the branch on the left side of the second slot 221, that is, the opening direction of the end of the main feeding branch of the first radiator 21 is rightward, the opening direction of the end of the main feeding branch of the second radiator 22 is rightward, and the opening directions of the ends of the two main feeding branches are the same.

When the electronic device is in the unfolded state, if the first radiator 21 and the second radiator 22 are not connected by using the radio frequency connection line, but the first radiator 21 is fed with the electric signal alone, the first radiator 21 and the ground may form a first antenna, which is a slot antenna, and similarly, the second radiator 22 is fed with the electric signal alone, and the second radiator 22 and the ground may form a second antenna, which is a slot antenna.

Fig. 17 is a return loss coefficient graph of the first antenna and the second antenna, S11 and S22 represent return loss characteristics of the first antenna and the second antenna, respectively, and S12 represents isolation of the first antenna and the second antenna. Fig. 18 is a graph of efficiency of the first and second antennas, E1 and E2 represent system efficiencies of the first and second antennas, respectively, and R1 and R2 represent radiation efficiencies of the first and second antennas, respectively. Referring to fig. 17 and 18, when an electrical signal is fed to each of the first antenna and the second antenna, the first antenna and the second antenna have equivalent performance, and both of the first antenna and the second antenna have two resonances, and two center resonance frequencies of the two antennas coincide with each other, where the first resonance frequency is 1.83GHz and the second resonance frequency is 2.61GHz. And the isolation between the first antenna and the second antenna is less than-13 dB, and the first antenna and the second antenna have good isolation.

The SAR values of the first antenna and the second antenna at the back and the bottom of the electronic equipment are simulated and normalized according to the-5 dB efficiency, and the SAR value result of the first antenna is shown in a table 5, and the SAR value result of the second antenna is shown in a table 6.

TABLE 5

TABLE 6

Referring to tables 5 and 6, it can be seen that the SAR values of the first antenna and the second antenna are high, and especially the normalized SAR value of the first antenna can reach 1.70W/Kg when the resonant frequency is 2.61GHz, which is a high SAR.

The hot spot pattern of the first antenna can be seen with reference to fig. 8a-8d, where the hot spot of the first resonance is concentrated at the main feed stub, the hot spot of the second resonance is concentrated at the coupling parasitic stub, and the hot spot of the second resonance is higher.

Fig. 19 a-19 d are schematic heat point diagrams of a second antenna, where fig. 19a and 19b are first resonances, fig. 19c and 19d are second resonances, fig. 19a and 19c are back surfaces, and fig. 19b and 19d are bottom surfaces. Referring to fig. 19 a-19 d, for the second antenna, the hot spots of the first resonance are more dispersed at the back surface and concentrated at the main feed stub at the bottom surface, and the hot spots of the second resonance are concentrated at the main feed stub at the back surface and are more dispersed at the bottom surface.

In this embodiment of the application, the feed source 23 and the radio frequency connection line 24 may refer to a structure in the first scenario, which is not described herein again.

The phase difference of the electrical signal arriving at the first radiator 21 and the second radiator 22 is controlled to simulate the SAR value and the hot spot distribution of the antenna at different phase differences, which may have three cases of same phase, 90 ° phase difference, and opposite phase, respectively, and the SAR value results of the antenna may be obtained as shown in tables 7a, 7b, and 7c, respectively.

TABLE 7a same phase

TABLE 7b phase difference of 90 °

TABLE 7c antiphase

Referring to tables 7a to 7c, it can be found that, in terms of simulation efficiency, efficiency of the same phase is higher than efficiency of the opposite phase by 90 ° in phase as a whole. In terms of SAR values, for the first resonance, the SAR value in the same phase is lower than that of the SAR value with the phase difference of 90 degrees and is lower than that of the opposite phase, and for the second resonance, the normalized SAR values are lower than 1W/Kg in the same phase and belong to low SAR.

Comparing the SAR value of the distributed antenna with the SAR values of the single antennas to which the electric signals are respectively fed, it can be found that the first resonant SAR value of the distributed antenna is higher than that of the single antenna when the electric signals reaching the first radiator and the second radiator are in opposite phases. When the electrical signals reaching the first radiator and the second radiator are in the same phase, the SAR value of the distributed antenna is obviously lower than that of a single antenna, so that the distributed antenna is arranged, the phase difference of the electrical signals reaching the first radiator and the second radiator is controlled, and the purpose of reducing the SAR value can be achieved.

Fig. 20 a-20 f are schematic heat-point diagrams of the antenna at a first resonance frequency with different phases, wherein fig. 20 a-20 c are back, fig. 20 d-20 e are bottom, fig. 20a and 20d are in phase, fig. 20b and 20e are 90 out of phase, and fig. 20c and 20f are in opposite phase. Referring to fig. 20 a-20 f, in the first resonance, from the same phase to the opposite phase, the hot spots on the back and bottom of the antenna are gradually concentrated, i.e. the SAR value is gradually increased.

Fig. 21 a-21 f are schematic heat point diagrams of the antenna at a second resonance frequency with different phases, wherein fig. 21 a-21 c are back, fig. 21 d-21 f are bottom, fig. 21a and 21d are in phase, fig. 21b and 21e are 90 ° out of phase, and fig. 21c and 21f are opposite phases. Referring to fig. 21a to 21f, under the second resonance, the hot spot is biased to be concentrated on the first radiator 21, the current distribution also exists on the second radiator 22, and a radiation branch of the first radiator 21 is separated between the hot spot concentrated region on the first radiator 21 and the hot spot concentrated region on the second radiator 22, so the SAR value is relatively low.

Fig. 22a to 22f are current distribution diagrams of antennas with different phases, in which fig. 22a to 22b are in phase, fig. 22c to 22d are 90 ° out of phase, fig. 22e to 22f are in opposite phase, fig. 22a, 22c and 22e are first resonances, and fig. 22b, 22d and 22f are second resonances. It should be noted that, because the structures of the two radiators on the two sides of the rotating shaft are not completely symmetrical, the current distribution on the first radiator 21 and the second radiator 22 is not uniform, and the thicker line in the figure indicates that the current distribution is more. When the CM or DM mode of the antenna is determined from the current distribution, the branches having more current distribution may be dominant.

Referring to fig. 22a, the current on the first radiator 21 is distributed in the same direction, which may be regarded as a CM pattern of the slot antenna, and the current on the second radiator 22 is distributed in the same direction, which may be regarded as a CM pattern of the slot antenna. The currents on the coupling parasitic branch with the stronger current on the first radiator 21 and the coupling parasitic branch with the stronger current on the second radiator 22 are distributed in the opposite direction, and can be regarded as a CM mode of the line antenna. That is, in the first resonance, when the electric signals reaching the first radiator 21 and the second radiator 22 are in phase, the common mode of the slot antenna on the single side can be converted into the common mode of the line antenna centered on the rotation axis 22 in the distributed antenna.

Referring to fig. 22b, the current on the first radiator 21 is reversely distributed, which can be regarded as a DM mode of the slot antenna, and the current on the second radiator 22 is reversely distributed, which can be regarded as a DM mode of the slot antenna. The current on the main feed branch with stronger current on the first radiator 21 and the current on the main feed branch with stronger current on the second radiator 22 are distributed in a reverse direction, and can be regarded as a CM mode of the line antenna. That is, in the second resonance, when the electric signals reaching the first radiator 21 and the second radiator 22 are in phase, the differential mode of the single-sided slot antenna can be converted into the common mode of the line antenna in the distributed antenna.

Referring to fig. 22c, the current on the first radiator 21 is distributed in the same direction, which may be regarded as a CM pattern of the slot antenna, and the current on the second radiator 22 is distributed in the same direction, which may be regarded as a CM pattern of the slot antenna. The currents on the first radiator 21 and the second radiator 22 are distributed in the same direction, and may be considered as a DM mode of the line antenna. Referring to fig. 22d, the current on the first radiator 21 is reversely distributed, which can be regarded as a DM mode of the slot antenna, and the current on the second radiator 22 is reversely distributed, which can be regarded as a DM mode of the slot antenna. The current on the main feed branch of the second radiator 22 is relatively strong, and the current on the main feed branch of the first radiator 21 and the current on the main feed branch of the second radiator 22 are distributed in the same direction, and may be regarded as a DM mode of a line antenna. That is, when the electric signals reaching the first radiator 21 and the second radiator 22 are different by 90 °, the common mode and the differential mode of the slot antenna of the single side may be converted into the differential mode of the line antenna in the distributed antenna. The difference compared to the schemes of fig. 22e and 22f is the magnitude of the two-sided current.

Referring to fig. 22e, the current on the first radiator 21 is distributed in the same direction, which may be regarded as a CM pattern of the slot antenna, and the current on the second radiator 22 is distributed in the same direction, which may be regarded as a CM pattern of the slot antenna. The current on the first radiator 21 and the current on the second radiator 22 are distributed in the same direction, and may be considered as a DM mode of the line antenna. That is, in the first resonance, when the electric signals reaching the first radiator 21 and the second radiator 22 are in opposite phases, the common mode of the slot antenna on the single side can be converted into the differential mode of the line antenna centered on the rotation axis 12 in the distributed antenna. Referring to fig. 22f, the current on the first radiator 21 is reversely distributed, which can be regarded as the DM mode of the slot antenna, and the current on the second radiator 22 is reversely distributed, which can be regarded as the DM mode of the slot antenna. The main feed branch of the first radiator 21 with stronger current and the main feed branch of the second radiator 22 with stronger current are distributed in the same direction, so as to form a DM mode of the line antenna. That is, in the second resonance, when the electric signals reaching the first radiator 21 and the second radiator 22 are in opposite phases, the differential mode of the slot antenna on one side can be converted into the differential mode of the line antenna in the distributed antenna.

In short, in the electronic device in the unfolded state, when the openings of the ends of the main feed branches of the first radiator 21 and the second radiator 22 are in the same direction, and the phase difference between the electric signals reaching the first radiator 21 and the second radiator 22 is in the same phase, the first resonant currents of the distributed antenna are symmetrically and reversely distributed around the rotating shaft, so when the electronic device is in the folded state, the current distributions of the adjacent parallel radiation branches on the first main body and the second main body are in the same direction; when the electronic equipment is in the unfolding state, the second resonant current is symmetrically distributed in the same direction by taking the rotating shaft as an axis, and although the current distribution is not uniform, when the electronic equipment is in the folding state, the current distribution of the adjacent parallel radiation branches on the first main body and the second main body is integrally embodied in the same direction. Thus, a high-performance, low-SAR antenna can be obtained.

Scene three

Fig. 23 is a schematic structural diagram of an antenna according to an embodiment of the present application. Referring to fig. 23, in the embodiment of the present application, the first radiator 21, the second radiator 22, and the four slots may refer to the structure in fig. 5 in the first scenario, and details thereof are not repeated.

In this embodiment, the first feeding point F1 feeds power to the branch on the left side of the first slot 211, and the second feeding point F2 feeds power to the branch on the right side of the second slot 221, that is, the opening direction of the end of the main feeding branch of the first radiator 21 is rightward, the opening direction of the end of the main feeding branch of the second radiator 22 is leftward, and the opening directions of the ends of the two main feeding branches are opposite to each other.

Fig. 24 is a return loss coefficient graph of the first antenna and the second antenna, S11 and S22 represent return loss characteristics of the first antenna and the second antenna, respectively, and S12 represents isolation of the first antenna and the second antenna. Fig. 25 is a graph of efficiency of the first and second antennas, E1 and E2 representing system efficiency of the first and second antennas, respectively, and R1 and R2 representing radiation efficiency of the first and second antennas, respectively. Referring to fig. 24 and 25, when an electrical signal is fed to each of the first antenna and the second antenna, the first antenna and the second antenna have equivalent performance, and both of the first antenna and the second antenna have two resonances, and two center resonance frequencies of the two antennas coincide with each other, where the first resonance frequency is 1.86GHz and the second resonance frequency is 2.6GHz. And the isolation between the first antenna and the second antenna is less than-13 dB, and the first antenna and the second antenna have good isolation.

The SAR values of the first antenna and the second antenna at the back and bottom of the electronic device are simulated and normalized according to-5 dB efficiency, and the SAR value results of the first antenna are shown in table 8 and the second antenna are shown in table 9.

TABLE 8

TABLE 9

Referring to tables 8 and 9, it can be seen that the SAR values of the first antenna and the second antenna are high, and especially the normalized SAR value of the first antenna at the resonant frequency of 1.86GHz can reach 1.20W/Kg, which is a high SAR.

Fig. 26 a-26 d are schematic heat-point diagrams of a first antenna, where fig. 26a and 26b are first resonances, fig. 26c and 26d are second resonances, fig. 26a and 26c are back surfaces, and fig. 26b and 26d are bottom surfaces. Referring to fig. 26 a-26 d, for the first antenna, the hot spot of the first resonance is concentrated at the main feed branch, the hot spot of the second resonance is concentrated at the coupling parasitic branch, and the hot spot of the first resonance is higher.

The hot spot patterns of the second antenna can be seen in fig. 19a to 19d, where the hot spots of the first resonance are distributed relatively at the back surface and are biased to be concentrated at the main feed branch, and at the bottom surface at the coupling parasitic branch, and the hot spots of the second resonance are concentrated at the coupling parasitic branch at the back surface and are distributed relatively at the bottom surface.

The phase difference of the electrical signal arriving at the first radiator 21 and the second radiator 22 is controlled to simulate the SAR value and the hot spot distribution of the antenna at different phase differences, which may have three cases of in-phase, 90-phase, and opposite phase, respectively, and the SAR value results of the antenna may be obtained as in tables 10a, 10b, and 10c, respectively.

TABLE 10a in phase

TABLE 10b phase difference 90 °

TABLE 10c antiphase

Referring to tables 10a to 10c, it can be found that, in terms of simulation efficiency, efficiency of the opposite phase is higher than efficiency of the same phase differing by 90 °. On the SAR value, for the first resonance, the normalized SAR value is lower than 1W/Kg under the phase difference of 90 degrees and the opposite phase, belonging to low SAR, and the normalized SAR value under the same phase is higher; for the second resonance, the SAR values in the opposite phase are lower overall than the SAR values in the same phase with a phase difference of 90 °. Overall, the SAR values in anti-phase are generally lower than the SAR values in phase by 90 °, in particular for the second resonance. It should be noted that in the first and second scenarios, the SAR reduction effect is mainly reflected in the first resonance, and in the present scenario, the SAR reduction effect is mainly reflected in the second resonance, which is because the radiation branches in the third scenario have different structures, and the system efficiency of the second resonance is higher.

Fig. 27 a-27 f are schematic heat-point diagrams of the antenna at the first resonance frequency with different phases, wherein fig. 27 a-27 c are back, fig. 27 d-27 f are bottom, fig. 27a and 27d are in phase, fig. 27b and 27e are 90 ° out of phase, and fig. 27c and 27f are in opposite phase. Referring to fig. 27a to 27f, in the first resonance, the hot spots on the back surface are always dispersed and the hot spots on the bottom surface are gradually dispersed from the same phase to the opposite phase, so that the SAR is reduced.

Fig. 28 a-28 f are schematic heat-point diagrams of the antenna at a second resonance frequency with different phases, wherein fig. 28 a-28 c are back, fig. 28 d-28 f are bottom, fig. 28a and 28d are in phase, fig. 28b and 28e are 90 ° out of phase, and fig. 28c and 28f are in opposite phase. Referring to fig. 28 a-28 f, in the second resonance, the hot spots on the back and bottom surfaces are gradually dispersed from the same phase to the opposite phase, and thus the SAR value is reduced.

Fig. 29a to 29f are current distribution diagrams of antennas at different phases, where fig. 29a to 29b show the same phase, fig. 29c to 29d show the phase difference of 90 °, fig. 29e to 29f show the opposite phase, fig. 29a, 29c, and 29e show the first resonance, and fig. 29b, 29d, and 29f show the second resonance. Referring to fig. 29a, the current on the first radiator 21 is distributed in the same direction, which may be regarded as a CM pattern of the slot antenna, and the current on the second radiator 22 is distributed in the same direction, which may be regarded as a CM pattern of the slot antenna. The currents on the first radiator 21 and the second radiator 22 are distributed in the same direction, and may be regarded as a DM mode of the line antenna. That is, in the first resonance, when the electric signals reaching the first radiator 21 and the second radiator 22 are in phase, the common mode of the slot antenna on the single side can be converted into the differential mode of the line antenna centered on the rotation axis 12 in the distributed antenna.

Referring to fig. 29b, the current on the first radiator 21 is reversely distributed, which can be regarded as a DM mode of the slot antenna, and the current on the second radiator 22 is reversely distributed, which can be regarded as a DM mode of the slot antenna. The current on the main feed branch of the first radiator 21 and the current on the main feed branch of the second radiator 22 are distributed in the same direction, and can be regarded as a DM mode of the slot antenna. That is, in the second resonance, when the electrical signals reaching the first radiator 21 and the second radiator 22 are in phase, the differential mode of the slot antenna on one side can be converted into the differential mode of the line antenna centered on the rotation axis 12 in the distributed antenna.

Referring to fig. 29c, the current on the first radiator 21 is distributed in the same direction, which may be regarded as a CM pattern of the slot antenna, and the current on the second radiator 22 is distributed in the same direction, which may be regarded as a CM pattern of the slot antenna. The currents on the first radiator 21 and the second radiator 22 are distributed in the same direction, and may be considered as a DM mode of the line antenna. Referring to fig. 29d, the current on the first radiator 21 is reversely distributed, which can be regarded as a DM mode of the slot antenna, and the current on the second radiator 22 is reversely distributed, which can be regarded as a DM mode of the slot antenna. The current on the main feed branch of the first radiator 21 and the current on the main feed branch of the second radiator 22 are distributed in the same direction, and may be regarded as a DM mode of the slot antenna. That is, when the electric signals reaching the first radiator 21 and the second radiator 22 are different by 90 °, the common mode and the differential mode of the slot antenna of the single side may be converted into the differential mode of the line antenna centering on the rotation shaft 12 in the distributed antenna. The difference compared to the solutions of fig. 29a and 29b is the different amplitude of the currents on both sides.

Referring to fig. 29e, the current on the first radiator 21 is distributed in the same direction, which may be regarded as a CM pattern of the slot antenna, and the current on the second radiator 22 is distributed in the same direction, which may be regarded as a CM pattern of the slot antenna. The currents on the first radiator 21 and the second radiator 22 are distributed in opposite directions, and may be regarded as a CM pattern of the line antenna. That is, in the first resonance, when the electric signals reaching the first radiator and the second radiator are in opposite phases, the common mode of the slot antenna on the one side can be converted into the common mode of the line antenna centered on the rotation axis 12 in the distributed antenna. Referring to fig. 29f, the current reverse distribution on the first radiator 21 can be regarded as the DM mode of the slot antenna, and the current reverse distribution on the second radiator 22 can be regarded as the DM mode of the slot antenna. The current on the main feed of the first radiator 21 and the current on the main feed of the second radiator 22 are distributed in opposite directions, and may be considered as a CM mode of the line antenna. That is, in the second resonance, when the electric signals reaching the first radiator and the second radiator are in opposite phases, the differential mode of the slot antenna on the one side can be converted into the common mode of the line antenna centered on the rotation axis 12 in the distributed antenna.

To sum up, the embodiment of the present application provides an antenna applied to a foldable electronic device, where a first radiator disposed on a first main body and a second radiator disposed on a second main body form a distributed antenna, and when the opening directions of the ends of main feed branches of the first radiator and the second radiator are opposite, a phase difference from an electric signal to the first radiator and the second radiator is controlled to be an opposite phase, so that when the electronic device is in an unfolded state, a common mode of a linear antenna can be formed, and effects of high efficiency, wide frequency, and low SAR value are achieved; meanwhile, when the electronic device is in a folded state, because the current directions of the adjacent parallel radiation branches on the first main body and the second main body are kept consistent, high efficiency and low SAR value can be realized.

It should be noted that, in the above three scenarios, the first radiator and the second radiator on the foldable electronic device may have an axisymmetric structure, so as to achieve better efficiency and lower SAR value. However, in practice, it is not required that the first radiator and the second radiator both have a strict axisymmetric structure, and the resonances of one side of the first radiator and one side of the second radiator are not required to be completely overlapped, and the radiators on both sides are both formed by the main feed branch and the coupling parasitic branch, and by controlling the phase difference reaching the radiators on both sides, the slot antenna differential mode and the common mode of the single-side antenna can form the common mode of the line antenna, so as to achieve high efficiency and low SAR value of the antenna, that is, the antenna falls into the protection scope of the embodiment of the present application.

In addition, the resonant frequency of the antenna provided in the embodiment of the present application is not limited to 1.8GHz and 2.6GHz mentioned in the above embodiments, and the resonant frequency of the antenna can be changed by changing the electrical lengths of the first radiator and the second radiator, changing the position of the slot, and setting the tuning element, so that the antenna provided in the embodiment of the present application is suitable for different frequency bands. The antenna provided by the embodiment of the application is not limited to two radiators as a distributed antenna, and actually, more radiators can be provided, and the antenna is applicable to a foldable electronic device which is suitable for one folding and is also suitable for a foldable electronic device which is suitable for two or more folding times.

The antenna provided by the embodiment of the application is applied to the foldable electronic device, and the common mode of the line antenna is realized through the symmetrical structure of the radiating bodies on two sides of the rotating shaft, so that the high efficiency and the low SAR value of the antenna are realized. On the basis, the application also provides some embodiments, and the symmetric antenna structure is constructed on other non-foldable electronic devices, and the phase difference is controlled, so that the common mode of the line antenna is realized, and the high efficiency and the low SAR value of the antenna are realized. The other non-foldable electronic devices may be, for example, a mobile phone, a tablet computer, and the like.

Another antenna structure provided in the present application is specifically described below with reference to specific drawings and embodiments by taking a tablet pc as an example.

Example two

Fig. 30 is a schematic structural diagram of a line antenna according to an embodiment of the present application. Referring to fig. 30, the line antenna may include a first radiator 21, a first feed 23, and a first feed point F1, and may be a T-type line antenna, that is, a line antenna in which a normal connection point is disposed on a radiator. The first radiator 21 may be disposed at or near the edge of the electronic device, and is made of a flexible circuit board, a laser, or a spraying process. The main board or the floor (the filling area in the figure) is arranged inside the electronic device, a certain gap is formed between the main board or the floor and the first radiator 21, and the first radiator 21 can be electrically connected with the main board in a metal elastic sheet mode and the like, so that feeding and grounding of the antenna are achieved.

The positions of the first feeding point F1 and the grounding point are not particularly limited in the line antenna provided in the embodiment of the present application. In a specific embodiment, the length of the first radiator 21 may be 28mm, and the grounding point is located at the right half section of the first radiator 21 and is 9mm away from the right end of the first radiator 21.

Feeding the first antenna with an electrical signal may simulate the resonant frequency of the first antenna. Fig. 31 is a graph of return loss coefficients corresponding to the antenna provided in fig. 30, and fig. 32 is a graph of efficiency of the antenna provided in fig. 30, in which the solid line represents system efficiency and the dashed line represents radiation efficiency. Referring to fig. 31 and 32, the line antenna may generate two resonances, a first resonance frequency of 1.91GHz and a second resonance frequency of 3.58GHz.

Fig. 33 a-33 b are current distribution diagrams of the antenna provided in fig. 30, fig. 33a being a first resonance and fig. 33b being a second resonance, wherein the solid line refers to the current on the radiator and the dashed line refers to the current on the board. Referring to fig. 33a, when the antenna is at the first resonance, the current is distributed in the reverse direction on the first radiator 21, i.e. the first resonance is the common mode of the line antenna. Referring to fig. 33b, when the antenna is at the second resonance, the current is distributed in the same direction on the first radiator 21, that is, the second resonance is a differential mode of the line antenna.

Taking the first antenna disposed at the position of the electronic device near the bottom frame as an example, the SAR values of the first antenna at the back and bottom of the electronic device are simulated and normalized according to-5 dB efficiency, and the results of the SAR values of the first antenna can be obtained as shown in table 11.

TABLE 11

Referring to table 11, it can be seen that the normalized SAR value of the first antenna can reach 2.25W/Kg at the resonant frequency of 3.58GHz, which is a high SAR.

Fig. 34 a-34 d are schematic heat-point diagrams of a first antenna, where fig. 34a and 34b are first resonances, fig. 34c and 34d are second resonances, fig. 34a and 34c are back surfaces, and fig. 34b and 34d are bottom surfaces. Referring to fig. 34 a-34 d, the back-side hot spot of the first resonance is more concentrated, the bottom-side hot spot of the second resonance is more concentrated, and the hot spot of the second resonance is more concentrated than that of the first resonance.

In order to reduce the SAR value of the line antenna, in the embodiment of the present application, a structure that the second radiator is axisymmetric is additionally arranged, and a phase difference between an electric signal and the first radiator and the second radiator is controlled, so that an antenna with high efficiency and a low SAR value is realized.

Hereinafter, based on the line antenna provided in fig. 30, two different antennas are configured according to scene four and scene five, and the structure of the antenna provided in the embodiment of the present application is specifically described with reference to the drawings.

Scene four

Fig. 35 is a schematic structural diagram of an antenna according to an embodiment of the present application. Referring to fig. 35, the antenna may include a feed source 24, a first radiator 21, a second radiator 22, and a third radiator 25, where the first radiator 21 and the second radiator 22 are respectively disposed at left and right sides of the third radiator 25, the first radiator 21 inputs an electrical signal through a first feed point F1, the second radiator 22 inputs an electrical signal through a second feed point F2, the first feed point F1 and the second feed point F2 are connected through a radio frequency connection line 24, and the third radiator 25 is grounded.

The first radiator 21 and the second radiator 22 may be disposed in axial symmetry with respect to the third radiator 25, and the first feeding point F1 and the second feeding point F2 may also be disposed in symmetry. The ground point of the first radiator 21 may be located at a side of the first feeding point F1 facing the third radiator 25, and the ground point of the second radiator 22 may be located at a side of the second feeding point F2 facing the third radiator 25.

The lengths of the first radiator 21 and the second radiator 22 are not particularly limited in the embodiment of the present application, for example, the length of the first radiator 21 and the second radiator 22 may be greater than 20mm, the length of the third radiator 25 is less than the lengths of the first radiator 21 and the second radiator 22, when the length of the third radiator 25 is too long, the generated resonance may affect the resonance of the first radiator 21 and the second radiator 22, and when the length is too short, the first radiator 21 and the second radiator 22 may be coupled to affect the antenna performance, and in a possible example, the length of the third radiator 25 may be between 5mm and 10 mm. The positions of the feeding point and the ground point on the first radiator 21 and the second radiator 22 are not particularly limited in the embodiment of the present application.

In a specific embodiment, the length of the first radiator 21 and the second radiator 22 may be 28mm, the distance between the first radiator 21 and the second radiator 22 may be 8mm, and the length of the third radiator 25 may be 6mm. The third radiator 25 may be connected in series with an inductor of 25nH and then grounded, and the third radiator 25 may generate a new resonance, which may be tuned by the inductor, so that the resonance efficiency is lower than the first resonance and incompatible with the main resonance efficiency. The distance between the ground point of the first radiator 21 and the right end of the first radiator 21 may be 9mm, and the distance between the ground point of the second radiator 22 and the left end of the second radiator 22 may be 9mm.

The phase difference of the electrical signals up to the first feeding point F1 and the second feeding point F2 can be controlled by controlling the length of the radio frequency connection line 24 or connecting a phase shifter on the radio frequency connection line 24. The phase difference of the electric signal reaching the first radiator 21 and the second radiator 22 is controlled to simulate the SAR value and the hot spot distribution of the antenna under different phase differences, for example, the phase difference may have three conditions of same phase, 90 ° difference, and opposite phase, and the efficiency of the antenna under different phase can be obtained.

Fig. 36 is a graph of radiation efficiency of the antenna provided in fig. 35 at different phases, and fig. 37 is a graph of system efficiency of the antenna provided in fig. 35 at different phases, where C1 represents the same phase, C2 represents the phase difference of 90 °, and C3 represents the opposite phase. Referring to fig. 36 and 37, the radiation efficiency of the antenna is relatively high in the same phase and 90 ° out of phase, while the radiation efficiency of the antenna is relatively low in the opposite phase; the system efficiency of the antenna in phase is higher than that of the antenna in phase difference of 90 ° and in opposite phase. Therefore, when the electrical signals reach the first radiator 21 and the second radiator 22 in phase, the performance of the antenna is optimal.

Fig. 38 a-38 b are current distribution diagrams of the antenna in phase, where fig. 38a is the first resonance and fig. 38b is the second resonance. Referring to fig. 38a, in the same phase, for the antenna at the first resonance, the current on the first radiator 21 is distributed in the reverse direction, the current on the second radiator 22 is distributed in the reverse direction, and the currents are distributed in the reverse direction on the first radiator 21 and the second radiator 22 as a whole. Referring to fig. 38b, in the antenna at the second resonance in the same phase, the current is distributed in the opposite direction on the first radiator 21 and the second radiator 22. According to the current flow direction, in the same phase, the first resonance and the second resonance form a symmetrical distribution structure with the third radiator 25 as an axis, and a common mode of the line antenna is formed.

The results of the SAR values of the antenna are shown in table 12, which are obtained by simulating the SAR values of the antenna at 5mm body on the back and bottom of the electronic device and normalizing according to-5 dB efficiency.

TABLE 12

Referring to table 12 and comparing table 11, it can be seen that, in the in-phase distributed line antenna, the back and bottom SAR values of the first resonance are decreased significantly, the back SAR value of the second resonance is maintained unchanged, and the bottom SAR value is decreased significantly.

Fig. 39 a-39 d are schematic heat-point diagrams of the antenna in phase, where fig. 39a and 39b are first resonances, fig. 39c and 39d are second resonances, fig. 39a and 39c are back surfaces, and fig. 39b and 39d are bottom surfaces. Referring to fig. 39 a-39 b, the hot spots of the first resonance are scattered on both the back and bottom surfaces, the back hot spot of the second resonance moves to a central position where the third radiator is located, and the bottom hot spots are scattered, so that the SAR value is low as a whole.

Fig. 40 is a simplified structural diagram of an antenna according to an embodiment of the present application. Referring to fig. 40, an antenna provided in the embodiment of the present application includes a first radiator 21, a second radiator 22, and a third radiator 25, where the third radiator 25 is located between the first radiator 21 and the second radiator 22, and a length of the third radiator 25 is smaller than lengths of the first radiator 21 and the second radiator 22; the first radiator 21 inputs an electric signal through the first feeding point F1, the second radiator 22 inputs an electric signal through the second feeding point F2, the first feeding point F1 and the second feeding point F2 are connected through the radio frequency connection line 24, the third radiator 25 is grounded, and phases of the electric signals reaching the first feeding point F1 and the second feeding point F2 are in phase.

It should be noted that the first radiator 21 and the second radiator 22 may be disposed in an axisymmetric manner with respect to the third radiator 25, and the first feeding point F1 and the second feeding point F2 are disposed in an axisymmetric manner with respect to the third radiator 25, so as to construct a common mode of the line antenna. However, in practice, the first radiator and the second radiator are not required to have a strict axisymmetric structure, and when the first radiator and the second radiator are close to the axisymmetric structure, the effect of a low SAR value close to the common mode of the line antenna can be achieved.

It should be noted that the position of the grounding point in the antenna may not be particularly limited. The grounding points may be arranged on the right side of the first feeding point F1 and the left side of the second feeding point F2 as in the above embodiments, or the grounding points may be embodied by matching and inductance to ground.

To sum up, the embodiment of the present application provides an antenna applied to an electronic device, where the first radiator and the second radiator are disposed on two sides of the third radiator and symmetrically distributed, and a phase difference of a control electrical signal reaching the first radiator and the second radiator is the same phase, so that a common mode of a line antenna can be formed, and effects of high efficiency, wide frequency and low SAR value are achieved.

Scene five

Fig. 41 is a schematic structural diagram of another antenna according to an embodiment of the present application. Referring to fig. 41, the antenna may include a first radiator 21 and a second radiator 22, and the first radiator 21 and the second radiator 22 have the same structure and are arranged in a left-right array. The first radiator 21 inputs an electrical signal through the first feeding point F1, the second radiator 22 inputs an electrical signal through the second feeding point F2, and the first feeding point F1 and the second feeding point F2 are connected by the radio frequency connection line 24.

The lengths of the first radiator 21 and the second radiator 22 are not particularly limited in the embodiment of the present application, and may be greater than 20mm, for example. When the distance between the first radiator 21 and the second radiator 22 is too large, it is not beneficial to the compact arrangement of the antenna on the electronic device, and when the distance is too small, the coupling between the first radiator 21 and the second radiator 22 may affect the performance of the antenna, and in a possible example, the distance between the first radiator 21 and the second radiator 22 may be between 6mm and 12 mm. The positions of the feeding point and the ground point on the first radiator 21 and the second radiator 22 are not particularly limited in the embodiments of the present application.

In a specific embodiment, the lengths of the first radiator 21 and the second radiator 22 may be 28mm, the distance between the first radiator 21 and the second radiator 22 may be 8mm, the distance between the ground point of the first radiator 21 and the right end of the first radiator 21 may be 9mm, and the distance between the ground point of the second radiator 22 and the left end of the second radiator 22 may be 9mm.

The phase difference of the electric signals up to the first feeding point F1 and the second feeding point F2 can be controlled by controlling the length of the radio frequency connection line 24 or connecting a phase shifter on the radio frequency connection line 24. The phase difference of the electrical signal reaching the first radiator 21 and the second radiator 22 is controlled to simulate the SAR value and the hot spot distribution of the antenna under different phase differences, for example, the phase difference may have three conditions of same phase, 90 ° difference and opposite phase, and the efficiency of the antenna under different phase can be obtained.

Fig. 42 is a graph of radiation efficiency of the antenna provided in fig. 41 at different phases, fig. 43 is a graph of system efficiency of the antenna provided in fig. 41 at different phases, C1 represents the same phase, C2 represents the phase difference of 90 °, and C3 represents the opposite phase. Referring to fig. 42 and 43, when the electrical signals reach the first radiator 21 and the second radiator 22 in phase, the system efficiency of the antenna is the highest, but the system efficiency is about 1dB different in phase and opposite phase, and the difference is small.

Fig. 44 a-44 b are current distribution diagrams of the antenna in phase, where fig. 44a is the first resonance and fig. 44b is the second resonance. Referring to fig. 44a, in the same phase, for the antenna at the first resonance, the current on the first radiator 21 is distributed in the opposite direction, the current on the second radiator 22 is distributed in the opposite direction, and the currents on the first radiator 21 and the second radiator 22 are distributed in the opposite direction as a whole, which can be regarded as forming a common mode of the line antenna. Referring to fig. 44b, in the antenna at the second resonance in the same phase, the currents are distributed in the same direction in the first radiator 21 and the second radiator 22, and it can be considered that a differential mode of the line antenna is formed.

It should be noted that the dotted arrows in the figure represent induced currents on the main board, the positions where the arrows are not drawn represent weak currents at the positions, the arrows in the figure only illustrate the distribution of the currents, and the length of the arrows does not represent the strength of the currents.

The results of the SAR values of the antenna obtained by simulating the SAR values of 5mm body at the back and bottom of the electronic device and normalizing according to-5 dB efficiency are shown in table 13.

Watch 13

Fig. 45 a-45 d are schematic heat-point diagrams of an antenna in phase, where fig. 45a and 45b are first resonances, fig. 45c and 45d are second resonances, fig. 45a and 45c are back surfaces, and fig. 45b and 45d are bottom surfaces. Referring to fig. 45 a-45 d, the hot spots of the first resonance are more dispersed at the back and bottom surfaces, and the back hot spots of the second resonance are very concentrated.

Fig. 46 a-46 b are current distribution diagrams of the antenna in opposite phases, where fig. 46a is the first resonance and fig. 46b is the second resonance. Referring to fig. 46a, in the antenna at the first resonance in the opposite phase, the current is reversely distributed on the first radiator 21 and the second radiator 22, and it can be considered that a common mode of the line antenna is formed. Referring to fig. 46b, in the antenna at the second resonance in the opposite phase, the current is reversely distributed on the first radiator 21 and the second radiator 22, and it can be considered that a common mode of the line antenna is formed.

The results of the SAR values of the antenna are obtained by simulating the SAR values of 5mm body at the back and bottom of the antenna and normalizing according to-5 dB efficiency, as shown in table 14.

TABLE 14

Referring to table 14 and comparing table 13, it can be seen that the SAR value of the second resonance in the opposite phase is significantly lower than that of the second resonance in the same phase by more than 3 dB.

Fig. 47a to 47d are schematic heat-point diagrams of the antenna in the opposite phase, in which fig. 47a and 47b are first resonances, fig. 47c and 47d are second resonances, fig. 47a and 47c are rear surfaces, and fig. 47b and 47d are bottom surfaces. Referring to fig. 47 a-47 b, the hot spots of the first resonance are more concentrated on the back surface and more dispersed on the bottom surface, and the back hot spots and the bottom wall hot spots of the second resonance are both very dispersed, and the SAR value is lower.

Generally, although the system efficiency of the antenna in the same phase is higher than that of the antenna in the opposite phase, the SAR value of the antenna in the same phase is much higher than that of the antenna in the opposite phase, the system efficiency difference is acceptable, and the SAR value difference is unacceptable, and the opposite phase with the lower SAR value is selected in comparison of the two phases. That is, when the first radiator 21 and the second radiator 22 are arranged in an array, the phase difference between the electrical signals reaching the first radiator and the second radiator may be controlled to be a phase-opposite bit, so as to reduce the SAR value of the antenna.

Fig. 48 is a simplified structural diagram of an antenna according to an embodiment of the present application. As can be seen from fig. 48, the antenna provided in the embodiment of the present application includes a first radiator 21 and a second radiator 22, where the first radiator 21 inputs an electrical signal through a first feeding point F1, the second radiator 22 inputs an electrical signal through a second feeding point F2, the first feeding point F1 and the second feeding point F2 are connected by a radio frequency connection line 24, and phases of the electrical signals reaching the first feeding point F1 and the second feeding point F2 are opposite.

It should be noted that the first radiator 21 and the second radiator 22 may have the same structure and be arranged in a left-right arrangement, and the position of the first feeding point F1 relative to the first radiator 21 and the position of the second feeding point F2 relative to the second radiator 22 may be the same.

It should be noted that the position of the grounding point in the antenna may not be particularly limited. The grounding points may be arranged on the right side of the first feeding point F1 and the right side of the second feeding point F2 as in the above embodiments, or the grounding points may be embodied by matching and inductance to ground.

To sum up, the embodiments of the present application provide an antenna applied to an electronic device, where the first radiator and the second radiator have the same structure and are arranged in a left-right direction, and a phase difference that the electrical signal reaches the first radiator and the second radiator is controlled to be an opposite phase, so that a common mode of the line antenna can be formed, and the effects of high efficiency, wide frequency, and low SAR value are achieved.

The antenna provided by the embodiment of the application is applied to electronic equipment, the first radiator and the second radiator are arranged, an axial symmetry structure is formed by the first radiator and the second radiator, electric signals reaching the first radiator and the second radiator are controlled to be in the same phase, or the first radiator and the second radiator are arranged in a left-right mode, electric signals reaching the first radiator and the second radiator are controlled to be in opposite phases, and therefore the SAR value of the antenna can be reduced.

It should be noted that, in the above embodiments, as can be seen from reference to the drawings, the feed source 23 is grounded, that is, the feed form is a symmetric feed, and the symmetric feed can be understood as that one end of the feed source is connected to the radiator, and the other end is grounded. In another possible implementation, fig. 49 is a schematic diagram of an antenna structure provided in an embodiment of the present application, and referring to fig. 49, the feed source 23 may be ungrounded, and the feed form may be an anti-symmetric feed (anti-symmetric feed), where the anti-symmetric feed is understood as that positive and negative two stages of the feed source are respectively connected to two ends of the radiator, and signals output by the positive and negative two stages of the feed source have the same amplitude and opposite phases, for example, 180 ° ± 10 ° apart. With an anti-symmetric feed, the phase difference between the signal source and the first radiator 21 and the second radiator 22 needs to be adjusted accordingly, and is not specifically described here.

In summary, in the antenna and the foldable electronic device provided in the embodiments of the present application, the radiators are respectively disposed in the spaces on the two bodies of the foldable electronic device, the two radiators are connected by the rf connection line to form a distributed antenna, the phase difference of the signals fed into the radiators on the two sides is controlled by the feed source, the current is reversely distributed on the radiators on the two sides of the rotating shaft in the unfolded state, a common mode of the outgoing antenna is constructed, the two radiators in the folded state form adjacent parallel radiators, and the current on the parallel radiators is distributed in the same direction, so that the high efficiency and the low SAR value of the antenna can be realized. In addition, compared with the case that the antennas are respectively arranged on the two bodies of the foldable electronic device, the distributed antenna is arranged in the embodiment of the application, so that more resonant modes and bandwidths can be obtained.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the embodiments of the present application, and are not limited thereto; although the embodiments of the present application have been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An antenna is applied to a foldable electronic device, the foldable electronic device comprises a rotating shaft, a first main body and a second main body, the first main body and the second main body are arranged on two sides of the rotating shaft, and the antenna comprises a feed source, a first radiating body, a second radiating body, a first feed point, a second feed point and a radio frequency connecting line;

the first radiator is arranged in the first main body, the second radiator is arranged in the second main body, one end, close to the rotating shaft, of the first radiator is grounded, one end, close to the rotating shaft, of the second radiator is grounded, the first radiator feeds in an electric signal through the first feeding point, the second radiator feeds in an electric signal through the second feeding point, the first feeding point and the second feeding point are connected through the radio frequency connecting line, a first gap is formed in the first radiator, and a second gap is formed in the second radiator;

the first feeding point and the second feeding point are both arranged between the first gap and the second gap, and the phases of electric signals of the first feeding point and the second feeding point are opposite; alternatively, the first and second electrodes may be,

the first feeding point is arranged on one side of the first gap far away from the second gap, the second feeding point is arranged on one side of the second gap far away from the first gap, and the phases of electric signals of the first feeding point and the second feeding point are opposite; alternatively, the first and second electrodes may be,

2. The antenna of claim 1, further comprising a phase shifter connected between the first feed point and the second feed point.

3. The antenna of claim 2, wherein the phase shifter is disposed within the first body or the second body.

4. The antenna of any one of claims 1-3, wherein the first radiator and the second radiator are disposed axisymmetrically with respect to the rotation axis, and wherein the first slot and the second slot are disposed axisymmetrically with respect to the rotation axis.

5. The antenna according to any of claims 1-4, wherein a third slot is further disposed on the first radiator, and a fourth slot is further disposed on the second radiator, the third slot being located on a side of the first slot facing away from the second radiator, the fourth slot being located on a side of the second slot facing away from the first radiator; the first feeding point and the second feeding point are both arranged between the third slot and the fourth slot.

6. The antenna of any one of claims 1-5, wherein the radio frequency connection comprises a cable or a flexible circuit board.

7. The antenna according to any one of claims 1-6, wherein when the foldable electronic device is in the unfolded state, the extending direction of the first radiator and the second radiator is perpendicular to the extending direction of the rotation axis, and a distance between the first radiator and the second radiator is smaller than a width of the rotation axis; when collapsible electronic equipment is in fold condition, first irradiator with the extending direction of second irradiator is unanimous, just first irradiator with the second irradiator is in coincide in collapsible electronic equipment's the thickness direction.

8. The antenna of claim 7, wherein when the foldable electronic device is in the unfolded state, the currents flowing through the first radiator and the second radiator are distributed in opposite directions; when collapsible electronic equipment is in fold condition, first irradiator with the electric current on the second irradiator is the syntropy and distributes.

9. The antenna of claim 7, wherein the first radiator is electrically connected to the shaft to ground through the shaft, and wherein the second radiator is electrically connected to the shaft to ground through the shaft.

10. The antenna of any one of claims 1-9, wherein a gap is provided between the first radiator and a ground plane, wherein the electrical connection between the first radiator and the ground plane forms a slot, wherein the electrical connection between the second radiator and the ground plane forms a slot, and wherein the electrical connection between the second radiator and the ground plane forms a slot.

11. The antenna according to any one of claims 1 to 10, wherein the first radiator is provided with tuning switches, two tuning switches are respectively disposed on both sides of the first slot, and the second radiator is provided with tuning switches, two tuning switches are respectively disposed on both sides of the second slot.

12. A foldable electronic device, comprising a hinge, a first body and a second body disposed on either side of the hinge, and an antenna according to any one of claims 1-11.

13. The foldable electronic device of claim 12, wherein the electronic device comprises a metal bezel, and the metal bezel on two sides of the hinge forms the first radiator and the second radiator respectively.

14. The foldable electronic device of claim 13, wherein a portion of a length of a top frame at a top of the electronic device or a bottom frame at a bottom of the electronic device forms the first radiator and the second radiator.

15. An antenna is characterized by comprising a feed source, a first radiator, a second radiator and a third radiator, wherein the first radiator, the second radiator and the third radiator extend on the same straight line, the third radiator is positioned between the first radiator and the second radiator, and the length of the third radiator is smaller than that of the first radiator and that of the second radiator;

the first radiator is fed with an electric signal through a first feed point, the second radiator is fed with an electric signal through a second feed point, the first feed point is connected with the second feed point through a radio frequency connecting line, the third radiator is grounded, and the phases of the electric signals reaching the first feed point and the second feed point are in the same phase.

16. The antenna of claim 15, wherein the first radiator and the second radiator are disposed axially symmetrically with respect to the third radiator, and wherein the first feed point and the second feed point are disposed axially symmetrically with respect to the third radiator; the grounding point of the first radiator is positioned on one side of the first feeding point facing the third radiator, and the grounding point of the second radiator is positioned on one side of the second feeding point facing the third radiator.

17. The antenna of claim 15, wherein a tuning inductance is connected to the third radiator, and wherein an efficiency of a resonance generated by the third radiator is lower than an efficiency of a resonance generated by the first radiator and the second radiator.

18. An antenna, characterized in that, including the feed and first irradiator and the second irradiator that extend on same straight line, first irradiator feeds in the signal of telecommunication through first feed point, the second irradiator feeds in the signal of telecommunication through the second feed point, first irradiator with the length of second irradiator is the same and be left and right sides arrangement, the position of first feed point on the first irradiator with the second feed point is in the position on the second irradiator is the same, first feed point with the second feed point passes through the radio frequency connecting wire and connects, arrives the phase place inverting of the signal of telecommunication of first feed point with the second feed point.

19. The antenna of claim 18, wherein the ground point of the first radiator is located on a side of the first feed point facing the second radiator, and wherein the ground point of the second radiator is located on a side of the second feed point facing away from the first radiator.

20. An electronic device, characterized in that it comprises an antenna according to any of claims 15-19.